Parkinson's Disease & Parkinson's Disease Dementia Drug Summary

Last updated: 16 February 2026
Reviewed by

Adenosine A2A Antagonist

Drug Dosage Remarks
Istradefylline ‘Wearing off’ episode treatment:
Initial dose: 20 mg PO 24 hourly
May increase dose based on response and tolerability
Max dose: 40 mg/day		 Adverse Reactions
  • CNS effects (dyskinesia, insomnia, dizziness, hallucinations, behavioral changes, confusion, delirium, delusion, disorientation, mania); GI effects (nausea, constipation, decreased appetite, diarrhea); Other effects (skin rashes, increased serum glucose, increased alkaline phosphatase, increased blood urea nitrogen, upper resp tract inflammation)
Special Instructions
  • Use with caution in patients with pre-existing dyskinesias, impulse control disorders, hepatic impairment

Anticholinergic Agents

Drug Dosage1 Remarks
Benzatropine (Benztropine) Adjunctive treatment:
Initial dose: 0.5-1 mg/day or 4-6 mg/day PO/IM usually at bedtime
May increase dose by 0.5 mg every 5-6 days
Max dose: 6 mg/day		 Adverse Reactions
  • Dose-related and reversible
  • Antimuscarinic effects (dry mouth, urinary retention, difficulty in swallowing, thirst, mydriasis, photophobia, dry skin, flushing, constipation, tachycardia, palpitations, arrhythmias); GI effects (nausea/vomiting); Other effects (rash, fever, heat stroke, weakness)
  • May also produce excitement and severe mental disturbances
Special Instructions
  • Contraindicated in patients with prostatic enlargement, paralytic ileus, pyloric stenosis, in patients with angle-closure glaucoma, myasthenia gravis
  • Use with caution in patients with tachycardia due to heart failure or thyrotoxicosis, hypertension or hypotension, renal or hepatic impairment
  • Use with caution in hot weather or during exercise, at risk are patients taking concurrent atropine-like drugs, alcoholics, with CNS disease and those with prolonged outdoor exposure
  • Monitor for anticholinergic syndrome
  • Withdraw drug gradually
Biperiden Initial dose: 1 mg PO divided 12 hourly
May increase dose by 2 mg/day
Maintenance dose: 3-16 mg/day PO in divided doses
Max dose: 16 mg/day
Diphenhydramine 25-50 mg PO 6-8 hourly
Max dose: 300 mg/day
or
10-50 mg IM/IV 6 hourly
May increase up to 100 mg IV at a rate <25 mg/min
Max dose: 400 mg/day
Orphenadrine Initial dose: 150 mg/day PO in divided doses
May increase dose gradually based on response with 50 mg every 2-3 days
Maintenance dose: 150-300 mg/day PO in divided doses
Max dose: 400 mg/day
Procyclidine Initial dose: 2.5 mg PO 8 hourly
May increase dose by 2.5-5 mg every 2-3 days
Maintenance dose: 10-30 mg/day PO divided 6-8 hourly
Max dose: 60 mg/day
For patients unable to take oral med or for emergency cases:
5-10 mg IV as a single dose or
5-10 mg IM every 20 minutes if required
Max dose: 20 mg/day
Trihexyphenidyl (Benzhexol) Adjunctive treatment:
Initial dose: 1-2 mg/day PO divided 6-8 hourly
May increase dose every 3-5 days by 2 mg increments up to 6-10 mg/day
Max dose: 20 mg/day
1Modified-release preparations are available. Specific prescribing information may be found in the latest MIMS.

Catechol-O-Methyltransferase (COMT) Inhibitors

Drug Dosage Remarks
Entacapone Adjunctive treatment:
200 mg/dose PO
Max dose: 2,000 mg/day		 Adverse Reactions
  • When administered as an adjunct to Levodopa, dopaminergic side effects may occur, most commonly at the start of treatment
  • Decreasing the dose of Levodopa may lessen the severity and frequency of dopaminergic side effects
  • GI effects (nausea/vomiting, abdominal pain, constipation, diarrhea, dry mouth); CV effect (orthostatic hypotension); Other effects (dyskinesia, body fluid discoloration, dizziness, dystonia, fatigue, increased sweating, fall)
Special Instructions
  • Recommended as adjunct to Levodopa with dopa-decarboxylase inhibitors
  • Administer dose at the same time as each dose of Levodopa/dopa-decarboxylase inhibitor does not exert anti-Parkinsonian effect on its own
  • Decrease Levodopa dose by 10-30%
  • Withdraw drug gradually, increase dose of Levodopa if required
  • Contraindicated in patients with hepatic impairment, pheochromocytoma, history of neuroleptic malignant syndrome or nontraumatic rhabdomyolysis
  • Use with caution in patients with renal or hepatic impairment
Opicapone Adjunctive treatment:
50 mg PO at bedtime
Max dose: 50 mg/day		 Adverse Reactions
  • GI effects (constipation, xerostomia); CV effects (orthostatic hypotension, hypertension); Other effects (dyskinesia, hallucinations, sleep disorders)
Special Instructions
  • Contraindicated in patients with concomitant use of monoamine oxidase inhibitors, patients with pheochromocytoma, paraganglioma or other catecholamine secreting neoplasms
  • Use with caution in patients with hepatic and renal impairment
  • Withdraw drug gradually, patients should be monitored closely if therapy is discontinued
Tolcapone Adjunctive treatment:
Initial dose: 100 mg PO 8 hourly
Max dose: 600 mg/day		 Adverse Reactions
  • GI effects (nausea, diarrhea, anorexia); CV effect (orthostatic hypotension); Other effects (dyskinesia, hallucinations, sleep disorder, fulminant liver failure which is sometimes fatal, yellow intensification in the color of urine)
  • When administered as an adjunct to Levodopa, may cause dizziness and orthostatic hypotension
Special Instructions
  • Recommended as an adjunct to Levodopa with dopa-decarboxylase inhibitors
  • Limited use due to risk of hepatotoxicity, use only when other adjunctive treatments have failed
  • Administer first dose at the same time as Levodopa/dopa-decarboxylase inhibitors
  • Decrease Levodopa dose if already on Levodopa dose of >600 mg/day
  • Contraindicated in patients with history of neuroleptic malignant syndrome, with non-traumatic rhabdomyolysis, hyperpyrexia and confusion, with renal or hepatic impairment
  • Monitor liver enzymes before and during treatment
    • Every 2 weeks for first year of therapy
    • Every 4 weeks for next 6 months
    • Every 8 weeks thereafter
    • Monitor during each dose increase
    • Discontinue if liver enzymes exceed the upper limit or if liver failure occurs
  • Withdraw drug gradually if inadequate response after 3 weeks of treatment

Dopamine Agonists

Drug Dosage Remarks
Ergot-derived
Bromocriptine 1-1.25 mg PO 24 hourly at night for first week
May increase to 2-2.5 mg PO 24 hourly at night for week 2, then 2.5 mg PO 12 hourly for week 3, then 2.5 mg PO 8 hourly for week 4
May increase by 2.5 mg every 3-14 days thereafter, if needed
Usual dose range: 10-30 mg/day PO or
10-80 mg/day PO in divided doses
Max dose: 100 mg/day PO		 Adverse Reactions
  • CNS effects (dizziness, fatigue, confusion, hallucinations, insomnia); GI effects (nausea/vomiting, gastric hemorrhage); CV effect (orthostatic hypotension)
  • Side effects (eg cardiac fibrosis) are generally dose-related and occur more frequently at high doses
  • Ergot-derived dopamine agonists are associated with risk of retroperitoneal and pulmonary fibrosis and erythromelalgia
Special Instructions
  • When administered as an adjunct, introduce gradually in patients already on Levodopa, decrease Levodopa dose gradually until optimal response is achieved
  • Contraindicated in patients with hypersensitivity to Bromocriptine and other ergot alkaloids, and those with uncontrolled hypertension, syncopal migraine
  • Use with caution in patients with CV disease, Serotonin syndrome, Raynaud’s syndrome, dementia, peptic ulcer disease, history of psychotic disorders
  • Monitor patient for retroperitoneal fibrosis and withdraw drug if fibrotic changes are observed
  • Perform minimum renal function tests, ESR prior to start of therapy and annually thereafter
Cabergoline Monotherapy:
Initial dose: 0.5-1 mg PO 24 hourly
Adjunctive treatment:
Initial dose: 1 mg PO 24 hourly
May increase dose by 0.5-1 mg every 7-14 days up to 2-3 mg/day PO
Lisuride Adjunctive treatment:
Initial dose: 100 mcg PO 24 hourly at bedtime
May add a dose of 100 mcg PO in the morning; 1 week later, add another dose of 100 mcg PO at midday
May continue to increase dose by 100 mcg weekly following the above sequence (at bedtime then in the morning and finally, at midday) until optimal response is achieved
Max dose: 2 mg/day
Non-ergot-derived
Apomorphine Withhold anti-Parkinson’s therapy overnight to provoke an “off” period followed by
Initial test dose range:
1 mg SC followed by 2 mg SC every 40 minutes at an increasing regimen to determine the lowest dose to produce a response
Once normal anti-Parkinson’s therapy is re-established:
Administer this dose at the first signs of the “off” period
May adjust dose based on response to 3-30 mg/day SC in divided doses with each injection ≤10 mg
For patients who require ≥10 injection/day or in patients with inadequate control:
Continuous infusion:
1 mg/hr SC
May increase dose by 0.5 mg/hr every ≥4 hours up to maximum of 4 mg/hr
May need infusion with intermittent bolus
Max dose (infusion and bolus):
100 mg/day and 10 mg/dose		 Adverse Reactions
  • CV effects (chest pain, orthostatic hypotension, tachycardia); GI effects (nausea/vomiting, increased salivation); CNS effects (dizziness, drowsiness, transient sedation, dyskinesia, falls, cognitive impairment, personality changes, confusion, visual hallucinations, euphoria, restlessness); Dermatologic effects (induration, nodule formation, panniculitis and ulceration may occur at SC injection site); Other effects (tremor, tachypnea, increased perspiration)
  • Co-administration with Levodopa may cause hemolytic anemia
    • Discontinue treatment if anemia is not controlled by dosage adjustment
Special Instructions
  • Not to be administered via IV
  • Pretreatment with antiemetics (eg Domperidone) for ≥2 days before administration of Apomorphine
  • Administer during waking hour, change infusion site every 12 hours
  • 24-hour infusions are not recommended unless there are severe nighttime symptoms
  • Contraindicated in patients with respiratory or CNS depression, hypersensitivity to opioids, neuropsychiatric problems or dementia
  • Not recommended in patients with “on” response to Levodopa marred by severe dyskinesia, hypotonia and psychiatric effects
  • Use with caution in patient with anatomical penile deformity, nausea/vomiting, pulmonary, CV disease or endocrine disorder, renal or hepatic impairment
  • Monitor hepatic, renal, hematopoietic, CV function periodically
  • Monitor for hemolytic anemia if co-administering with Levodopa before treatment and every 6 months
  • Patients who developed hemolytic anemia, continuing confusion or hallucinations may require specialist observation and dose adjustment, discontinue treatment if not controlled
Piribedil Monotherapy:
Usual dose: 150-250 mg/day PO in 3-5 divided doses
Combination with Levodopa therapy:
50-150 mg/day PO in 1-3 divided doses		 Adverse Reactions
  • Minor GI effects (nausea/vomiting, flatulence) in predisposed patients or when taken between meals, orthostatic hypotension, drowsiness, hallucinations, confusion
Special Instructions
  • When administered as an adjunct, introduce gradually in patients already on Levodopa, decrease Levodopa dose gradually until optimal response is achieved
  • Avoid in patients with circulatory collapse or acute MI
Pramipexole Monotherapy and adjunctive treatment:
Initial dose:
First week: 125 mcg PO 8 hourly
Second week: 250 mcg PO 8 hourly
Third week: 500 mcg PO 8 hourly
May increase dose based on response by 750 mcg/day at weekly intervals up to:
Max dose: 4.5 mg/day
Extended-release:
First week: 0.375 mg PO 24 hourly
Second week: 0.75 mg PO 24 hourly
Third week: 1.5 mg PO 24 hourly
May increase dose by 0.75 mg/day at weekly intervals up to:
Max dose: 4.5 mg/day		 Adverse Reactions
  • Same as for Bromocriptine
  • Sudden onset of sleep with or without feeling of drowsiness
Special Instructions
  • Same as for Bromocriptine
  • When administered as an adjunct, introduce gradually in patients already on Levodopa, decrease Levodopa dose gradually until optimal response is achieved
  • Use with caution in patients with psychotic disorder
  • Reduce dose in patients with renal impairment
  • Do not drive or perform potentially hazardous activities eg operate machinery
  • Withdraw drug gradually to avoid neuroleptic malignant syndrome
    • Taper dose by 750 mcg/day to daily dose of 750 mcg/day then further taper dose by 375 mcg/day
  • Monitor blood pressure, ophthalmologic testing is recommended due to risk of visual disorders
Ropinirole Monotherapy and adjunctive treatment:
Immediate release:
Initial dose: 250 mcg PO 8 hourly
May increase dose by 250 mcg PO 8 hourly weekly x first 4 weeks
May further increase dose up to 3 mg/day weekly
Usual dose range: 3-9 mg/day PO
Max dose: 24 mg/day
Extended-release:
Initial dose: 2 mg PO 24 hourly
Dose titration for the first 4 weeks of therapy:
Week 1: 2 mg PO 24 hourly
Week 2: 4 mg PO 24 hourly
Week 3: 6 mg PO 24 hourly
Week 4: 8 mg PO 24 hourly
Max dose: 24 mg/day		 Adverse Reactions
  • CNS effects (somnolence, dizziness, hallucinations, vertigo); GI effects (nausea/vomiting, constipation); CV effect (postural hypotension); Other effect (dyskinesia)
  • Sudden onset of sleep with or without feeling of drowsiness
Special Instructions
  • Same as for Bromocriptine
  • When administered as an adjunct, introduce gradually in patients already on Levodopa, decrease Levodopa dose gradually until optimal response is achieved (decrease by 20-30% gradually)
  • Do not drive or perform potentially hazardous activities eg operate machinery
  • Withdraw drug gradually by decreasing the number of daily doses over 1 week
  • Avoid in patients with severe hepatic impairment
  • Use with caution in patients with severe CV disease, severe renal impairment or end-stage renal disease, history or presence of major psychotic disorders

Dopamine Agonist (Transdermal)

Drug Available Strength Dosage Remarks
Rotigotine 2 mg/24 hr (10 cm2)
4 mg/24 hr (20 cm2)
6 mg/24 hr (30 cm2)
8 mg/24 hr (40 cm2)		 Monotherapy:
Initially, single dose of 2 mg/day, then may increase dose by 2 mg/24 hr each week thereafter until effective dose is reached (eg 2 mg/24 hr in week 1, 4 mg/24 hr in week 2)
Usual maintenance dose: 6-8 mg/24 hr patch (reached within 3-4 weeks)
Max dose: 8 mg/24 hr patch
Combination with Levodopa: Initially, 4 mg/24 hr, then may increase with increments of 2 mg weekly thereafter
Usual maintenance dose: 8-16 mg/24 hr patch (reached within 3-7 weeks)
Max dose: 16 mg/24 hr patch		 Adverse Reactions
  • CNS effects (somnolence, dizziness, hallucinations, insomnia, headache); GI effects (nausea/vomiting, anorexia, constipation, diarrhea, dry mouth, dyspepsia); CV effects (orthostatic hypotension, hypertension); Other effects (dyskinesia, lethargy, hiccup, cough, hyperhidrosis, asthenic conditions, peripheral edema)
  • May cause reactions to application site (eg erythema and pruritus)
Special Instructions
  • Same as for Bromocriptine
  • Apply on intact skin area which should be clean, dry and hairless
  • Rotate application site daily
  • Avoid applying a new patch to the same spot for at least 14 days
  • Remove patch prior to MRI or cardioversion to avoid burns
  • Monitor BP regularly during therapy
  • Do not drive or perform potentially hazardous activities (eg operate machinery)
  • Contraindicated in patients with hypersensitivity to Rotigotine
  • Use with caution in patients with severe hepatic impairment
  • Withdraw drug gradually to avoid occurrence of neuroleptic malignant syndrome

Dopamine Precursors

Drug Dosage Remarks
Dopamine Precursor Combinations
Levodopa/Benserazide 1 part of Benserazide to 4 parts of Levodopa:
*Doses based on Levodopa
Patients not previously treated with Levodopa or previously treated with other Levodopa/dopa-decarboxylase inhibitors:
Initial dose: 50 mg PO 6-8 hourly
Increase the dose gradually in increments of 100 mg PO 1-2x/week
Optimal dose: 400-800 mg/day PO divided in ≥3 doses
4-6 weeks may be needed to achieve the optimal effect
Maintenance dose: 100 mg PO 3-6x/day
Patients previously treated with Levodopa:
10-15% of the previous dose should be administered		 Adverse Reactions
  • Nausea and vomiting may be diminished by increasing dose of Levodopa gradually, taking dose with or after meals
  • CV effects (orthostatic hypotension, tachycardia, arrhythmia); GI effect (anorexia); CNS effects (insomnia, agitation, dizziness, somnolence, sudden onset of sleep episodes)
  • Involuntary movement and psychiatric complications are the most common dose-limiting effect
  • ‘On-off’ effect may increase in frequency as therapy progresses
Special Instructions
  • Adjust interval between doses to meet individual needs
  • Max improvement may take up to >6 months
  • Start with low divided doses to minimize side effects and titrate upward to desired serum concentration, desired response and max tolerated side effects
  • Duration of benefit of each dose may become progressively shorter
  • Contraindicated in patients with angle-closure glaucoma
  • Use with caution in patients with open-angle glaucoma, CV disease, pulmonary disease, endocrine disorders, psychiatric disturbances, osteomalacia, history of peptic ulcerations, skin disorders
  • Periodic clinical monitoring of renal, hepatic, psychiatric, hematological and CV functions
Levodopa/Carbidopa 1 part of Carbidopa to 4 parts of Levodopa or 1 part of Carbidopa to 10 parts of Levodopa:
Immediate-release:
Patients not previously treated with Levodopa:
Initial dose: Carbidopa 10 mg/Levodopa 100 mg PO 6-8 hourly or
Carbidopa 12.5 mg/Levodopa 50 mg PO 6-8 hourly or
Carbidopa 25 mg/Levodopa 100 mg PO 8 hourly
May increase dose gradually by Carbidopa 12.5 mg/Levodopa 50 mg or Carbidopa 25 mg/Levodopa 100 mg every other day
Maintenance dose: Carbidopa 75-200 mg/day and Levodopa 0.75-2 g/day PO in divided doses
Substitute with 1 part of Carbidopa to 10 parts of Levodopa if less Carbidopa is required. Provide at least 75-100 mg Carbidopa/day
Patients previously treated with Levodopa:
20-25% of the previous dose should be administered
Max dose (Carbidopa): 200 mg/day
Max dose (Levodopa): 2,000 mg/day
Extended-release:
Patients not previously treated with Levodopa:
Initial dose: Carbidopa 50 mg/Levodopa 200 mg PO 12 hourly adjusted according to response at least every 3 days
Patients previously treated with Levodopa:
Initial dose similar to immediate-release preparation but dosing intervals should be prolonged and normally every 4-12 hourly; Adjust dose at least every 3 days according to response
Maintenance dose: Carbidopa 100-400 mg/day and Levodopa 0.4-1.6 g/day PO in divided doses		 Adverse Reactions
  • Nausea and vomiting may be diminished by increasing dose of Levodopa gradually, taking dose with or after meals
  • CV effects (orthostatic hypotension, tachycardia, arrhythmia); GI effect (anorexia); CNS effects (insomnia, agitation, dizziness, somnolence, sudden onset of sleep episodes)
  • Involuntary movement and psychiatric complications are the most common dose-limiting effect
  • ‘On-off’ effect may increase in frequency as therapy progresses
Special Instructions
  • Adjust interval between doses to meet individual needs
  • Max improvement may take up to >6 months
  • Start with low divided doses to minimize side effects and titrate upward to desired serum concentration, desired response and max tolerated side effects
  • Duration of benefit of each dose may become progressively shorter
  • Contraindicated in patients with angle-closure glaucoma
  • Use with caution in patients with open-angle glaucoma, CV disease, pulmonary disease, endocrine disorders, psychiatric disturbances, osteomalacia, history of peptic ulcerations, skin disorders
  • Periodic clinical monitoring of renal, hepatic, psychiatric, hematologic and CV functions
Dopamine Precursor Combination with COMT Inhibitor
Levodopa/Carbidopa/Entacapone 1 part of Carbidopa to 4 parts of Levodopa with Entacapone 200 mg:
*1 tab contains 1 treatment dose
Patients currently treated with standard-release Levodopa with Carbidopa and separate Entacapone in doses equal to the available tab strengths: Switch to the available tab strength
Patients previously treated with Levodopa with Carbidopa and separate Entacapone in doses not equal to the available tab strengths: Adjust dose to correspond closely as possible to the total daily dose of Levodopa currently used
Patients currently treated with Levodopa with Benserazide in a standard-release formulation and separate Entacapone:
Stop the treatment for 1 night and start the new dose the next morning
Begin dose that will provide either the same amount of Levodopa or slightly 5-10% more
Max dose for 50-150 mg Levodopa/12.5-37.5 mg Carbidopa/200 mg Entacapone fixed combination: 10 tabs/day
Max dose for 200 mg Levodopa/50 mg Carbidopa/200 mg Entacapone fixed combination: 7 tabs/day		 Adverse Reactions
  • Nausea and vomiting may be diminished by increasing dose of Levodopa gradually, taking dose with or after meals
  • CV effects (orthostatic hypotension, tachycardia, arrhythmia); GI effect (anorexia); CNS effects (insomnia, agitation, dizziness, somnolence, sudden onset of sleep episodes)
  • Involuntary movement and psychiatric complications are the most common dose-limiting effect
  • ‘On-off’ effect may increase in frequency as therapy progresses
Special Instructions
  • Adjust interval between doses to meet individual needs
  • Max improvement may take up to >6 months
  • Start with low divided doses to minimize side effects and titrate upward to desired serum concentration, desired response and max tolerated side effects
  • Duration of benefit of each dose may become progressively shorter
  • Contraindicated in patients with angle-closure glaucoma
  • Use with caution in patients with open-angle glaucoma, CV disease, pulmonary disease, endocrine disorders, psychiatric disturbances, osteomalacia, history of peptic ulcerations, skin disorders
  • Periodic clinical monitoring of renal, hepatic, psychiatric, hematologic and CV functions

Monoamine Oxidase B Inhibitors

Drug Dosage Remarks
Rasagiline Monotherapy and adjunctive treatment:
Initial dose:
1 mg PO 24 hourly		 Adverse Reactions
  • Rasagiline: CV effects (chest pain, orthostatic hypotension); CNS effects (headache, hallucination, depression); GI effects (dyspepsia, anorexia); Other effects (flu-like syndrome, malaise, leukopenia, arthralgia, arthritis, urinary urgency)
  • Safinamide: CNS effects (dyskinesia, falls, insomnia); GI effect (nausea)
  • Selegiline: When administered as an adjunct, most side effects are due to enhanced Levodopa activity
    • When administered as monotherapy: GI effects (nausea/vomiting, constipation, dry mouth, sore throat, stomatitis); CV effects (orthostatic hypotension, chest pain); CNS effects (dizziness, confusion, hallucination, insomnia); Other effects (tremor, vertigo, psychosis, depression, agitation, myopathy, joint pain, increased dyskinesia, increased liver enzymes)
Special Instructions
  • Do not use with other MAO inhibitors, Meperidine, Tramadol, Methadone, Pethidine, Dextromethorphan
  • When administered as adjunct to Levodopa, may decrease Levodopa dose by 10-50%
  • Selegiline: Use with caution in patients with hepatic or renal impairment, peptic ulcerations, uncontrolled hypertension, angina, arrhythmias, psychosis, pheochromocytoma; avoid in patients with active ulcerations
    • Do not use with TCAs, SSRIs and Venlafaxine
  • Rasagiline: Contraindicated in patients with moderate to severe hepatic impairment, or pheochromocytoma
    • Do not use with other sympathomimetic amines (eg Ephedrine)
    • Do not use with TCAs, SSRIs and SNRIs; use has been associated with rare reactions including Serotonin syndrome
  • Safinamide: Contraindicated in patients with severe hepatic impairment
    • Should not be taken concomitantly with Dextromethorphan, opioids, other MAO inhibitors, SNRIs, antidepressants or Cyclobenzaprine
  • Monitor blood pressure; perform skin exam periodically due to increased risk for melanoma
Safinamide Adjunctive treatment
Initial dose:
50 mg PO 24 hourly
May increase after 2 weeks to 100 mg PO 24 hourly, if needed
Selegiline Monotherapy and adjunctive treatment:
Initial dose:
5-10 mg PO 24 hourly in the morning or 12 hourly (in the morning and early afternoon)
Max dose: 10 mg/day

Others

Drug Dosage Remarks
Adamantane
Amantadine Monotherapy: 100 mg PO 12 hourly
May increase dose to 200 mg PO 12 hourly after 1 week
Max dose: 600 mg/day PO in divided doses		 Adverse Reactions
  • Side effects are dose-related and relatively mild, reversible on withdrawal of therapy
  • Livedo reticularis associated with ankle edema may occur with long-term treatment; CNS effects (nervousness, inability to concentrate, dizziness, insomnia, nightmares, headache, mood changes, hallucinations, convulsions); CV effects (orthostatic hypotension, CHF); GI effects (nausea/vomiting, anorexia, dry mouth, constipation); Other effects (urinary retention, slurred speech, ataxia, lethargy, skin rashes, blurred vision, facial dyskinesia, blood dyscrasia)
  • May cause blurred vision or impaired alertness
Special Instructions
  • ECG should be monitored before the start of therapy, 1 week after therapy and 3 weeks after therapy
    • QTc should be determined manually
  • Contraindicated in patients with severe renal disease, severe decompensated heart failure, 2nd or 3rd degree AV block, myocarditis, Torsade de pointes, QT prolongation, untreated angle-closure glaucoma, history of epilepsy, seizures and gastric ulcerations
  • Use with caution in patients with CV disease, hepatic disease, impaired renal function, recent eczema or psychosis
  • Patients often experience decrease in efficacy after a few months of use
  • Withdraw drug gradually by 50% at weekly intervals
    • Neuroleptic malignant syndrome has been observed with abrupt withdrawal when administered with antipsychotics
Muscle Relaxant (Centrally-Acting)
Tolperisone 50-150 mg PO 8 hourly Adverse Reactions
  • Headache, transient physical asthenia, nausea/vomiting, abdominal discomfort
Special Instructions
  • Should be taken with food
  • Contraindicated in patients with myasthenia gravis
Nootropic Agent
Citicoline 500 mg IV 24 hourly for 3-4 weeks with an anticholinergic
or
250-500 mg IV 24 hourly 2-3x/week with an anticholinergic
or
500-2,000 mg PO 24 hourly		 Adverse Reactions
  • Parasympathetic stimulation, hypotension, GI disorders
Special Instructions
  • Contraindicated in patients with parasympathetic hypertonia
Peripheral Vasodilator
Nicergoline 5-10 mg PO 8 hourly or
30 mg PO 12 hourly		 Adverse Reactions
  • GI effects (nausea, increased appetite); CV effects (syncope, hypotension, bradycardia); CNS effects (insomnia, agitation, dizziness)

Cholinesterase inhibitor (Oral)

DRUGS FOR PARKINSON'S DISEASE DEMENTIA
Drug Dosage Remarks
Rivastigmine Initial dose: 1.5 mg PO 12 hourly
May increase after ≥2 weeks, if tolerated, to 3 mg PO up to 4.5 mg PO 12 hourly
Max dose: 12 mg/day
Elderly or in renal/hepatic impairment:
Dosage adjustments are not recommended and titrate based on the patient’s tolerance		 Adverse Reactions
  • CNS effects (headache, dizziness, confusion, agitation, depression, insomnia, tremor); GI effects (abdominal pain, diarrhea, dyspepsia, nausea/vomiting, anorexia); Other effects (sweating, malaise, fatigue, asthenia)
  • Rarely angina, gastric and duodenal ulcers, seizures, rashes
Special Instructions
  • Take doses with breakfast and dinner
  • If medication is missed for several days, restart at lowest dose and increase to current dose
  • Treatment should be maintained at max tolerated dose
  • Avoid in patients with severe hepatic impairment
  • Use with caution in patients with sick sinus syndrome or other cardiac conduction abnormalities (AV block), history of seizures, history of asthma or other obstructive lung diseases, risk of gastric ulcer disease, or in patients with urinary obstruction

Cholinesterase Inhibitor (Transdermal)

DRUGS FOR PARKINSON'S DISEASE DEMENTIA
Drug Available Strength Dosage Remarks
Rivastigmine 5 cm2 patch contains
9 mg Rivastigmine AND delivers 4.6 mg/24 hr
10 cm2 patch contains
18 mg Rivastigmine and delivers 9.5 mg/24 hr
15 cm2 patch contains
27 mg Rivastigmine and delivers 13.3 mg/24 hr		 Initial dose: Apply 4.6 mg/24 hr patch 24 hourly
After a minimum of 4 weeks, may increase to
Maintenance dose:
9.5 mg/24 hr patch
Max dose:
13.3 mg/24 hr patch		 Adverse Reactions
  • The following effects are associated with higher-than-recommended dose: CNS effects (headache, confusion, dizziness, agitation, depression, insomnia, tremor); GI effects (abdominal pain, diarrhea, dyspepsia, nausea/vomiting, anorexia); Other effects (sweating, malaise, fatigue, asthenia)
  • Rarely angina, gastric and duodenal ulcers, seizures, rashes
Special Instructions
  • Apply to the upper back, lower back, upper arm or chest; area should be clean, dry, hairless and with intact skin
  • Avoid applying a new patch to the same spot for at least 14 days
  • Monitor weight during therapy
  • If clinical assessment showed no improvement after 3 months of maintenance therapy, patch should be stopped
  • Use with caution in patients with sick sinus syndrome or other cardiac conduction abnormalities (AV block), history of seizures, asthma or other obstructive lung diseases, risk of gastric ulcer disease, or in patients with urinary obstruction
  • If treatment is missed once, apply a new patch immediately. If treatment is missed for several days, restart with 4.6 mg/24 hr patch and titrate to the next dose after 4 weeks

N-Methyl-D-Aspartate (NMDA)-Receptor Antagonist

DRUGS FOR PARKINSON'S DISEASE DEMENTIA
Drug Dosage Remarks
Memantine First week: 5 mg/day PO
Second week: 10 mg/day PO
Third week: 15 mg/day PO
Fourth week and thereafter: 20 mg/day PO
Max dose: 20 mg/day
Moderate renal impairment:
10 mg/day PO		 Adverse Reactions
  • CNS effects (confusion, somnolence, agitation, dizziness, headache, insomnia, hallucinations); Urogenital effects (cystitis, urinary incontinence); GI effects (constipation, vomiting, weight loss); CVS effects (hypertension, syncope); Other effects (abnormal gait, hypertonia, increased libido)
Special Instructions
  • Use with caution in patients with severe renal dysfunction, recent MI, uncontrolled hypertension, epilepsy, patients with conditions that raise urine pH or chronic heart failure (CHF)
  • Avoid use with other NMDA antagonists (eg Amantadine, Dextromethorphan or Ketamine)

Disclaimer

All dosage recommendations are for non-pregnant and non-breastfeeding women, and non-elderly adults with normal renal and hepatic function unless otherwise stated.  
Not all products are available or approved for above use in all countries.  
Products listed in the Drug Summary are based on indications stated in the locally approved product monographs.   
Please refer to local product monographs in Related MIMS Drugs for country-specific prescribing information.  

Related MIMS Drugs