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Full Prescribing Info
Amlodipine besilate.
Each tablet contains: Amlodipine besilate, USP eq. to Amlodipine 5 mg.
Amlodipine besilate, USP eq. to Amlodipine 10 mg.
Pharmacology: Mechanism of action: Amlodipine besilate is a calcium-ion influx inhibitors (slow-channel blocking agents). Although their mechanism is not completely understood, they are thought to inhibit calcium ion entry through select voltage-sensitive areas termed "slow channels" across cell membranes. By reducing intracellular calcium concentration in cardiac and vascular smooth muscle cells, they dilate coronary arteries and peripheral arteries and arterioles, and may reduce heart rate, decrease myocardial contractility (negative inotropic effect), slow atrioventricular (AV) nodal conduction. Amlodipine is selective for vascular smooth muscles compared with myocardium and therefore act primarily as vasodilators. Hypotensive effects are accompanied by reflex tachycardia. However, Amlodipine appears to have no significant effect on the sinoatrial (SA) or atrioventricular (AV) node in humans.
Antianginal: Dilation of the peripheral vasculature reduces systemic pressure or cardiac afterload, which results in lessened myocardial wall tension and reduced oxygen requirements of the myocardial tissues. In vasospastic angina, a relaxation of coronary arteries and arterioles and inhibition of coronary artery spasm improves blood flow and oxygen supply to myocardial tissues may also be related to enhanced left ventricular diastolic relaxation and decreased wall stiffness (improved diastolic compliance). In vasospastic angina, Amlodipine blocks constriction and restores blood flow in coronary arteries and arterioles in response to Calcium, Potassium, Epinephrine, serotonin, and thromboxane A2 analog in human coronary vessels in vitro.
Antihypertensive: Reduction of total peripheral vascular resistance as a result of vasodilation.
Pharmacokinetics: Absorption: Bioavailability 64 to 90% absorption, not affected by food.
Protein binding: Very high (93%).
Biotransformation: Extensive hepatic metabolism; 90% converted to inactive metabolites.
Half-life-(biphasic) Elimination: 30 to 50 hours (terminal).
Time to peak concentration: 6 to 12 hours.
Time to peak effect: Time to steady-state plasma concentration: 7 to 8 days.
Elimination-Renal: 60% as metabolites and 10% as unchanged Amlodipine.
Angina pectoris, chronic (treatment): Amlodipine is indicated in the management of classic angina (chronic stable angina or effort associated angina) with no evidence of vasospasm. It is also indicated in vasospastic angina (Prinzmetal is variant, or at-rest angina) or unstable angina in patients who are unable to tolerate or whose symptoms are not relieved by adequate doses of beta-adrenergic blocking agents or organic nitrates. They are generally indicated when vasospastic angina is confirmed by: (a) the classical pattern accompanied by elevation of ST segment; (b) Ergonovine induced angina or coronary artery spasm; or (c) coronary artery spasm demonstrated by angiography, although they may also be used when vasospastic component is indicated but not confirmed (e.g. where pain has variable threshold on exertion or in unstable angina where electrocardiographic findings are compatible with intermittent vasospasm).
Hypertension: Amlodipine is indicated alone or in combination with other agents for treatment of hypertension.
Dosage/Direction for Use
Oral: Usual adult dose: 5 mg to 10 mg once a day.
Usual adult prescribing limits: 10 mg daily.
Usual pediatric dose: Safety and efficacy have not been established.
Usual geriatric dose: See Usual adult dose.
Note: An initial antihypertensive dose of 2.5 mg once a day is recommended for small, fragile or elderly patients with hepatic insufficiency, or with adding Amlodipine to other antihypertensive therapy. In general, titration should proceed over 7 to 14 days. Titration may proceed more rapidly if clinically warranted provided the patient is assessed frequently. Most patients will require 10 mg daily for adequate effect.
Clinical effects of overdose: Symptomatic hypotension; Reflex tachycardia; Bradycardia.
Treatment of overdose: To decrease absorption: Ipecac is not recommended since emesis may produce vagal stimulation and (theoretically) worsen an overdose with calcium antagonists. Furthermore, Ipecac has not been demonstrated to improve patient outcome.
Consider prehospital administration of activated charcoal as an aqueous slurry in patients who are awake and able to protect their airway. Activated charcoal is most effective when administered within one hour of ingestion.
To enhance elimination: High protein binding of all calcium channel blocking agents would suggest hemodialysis or hemoperfusion would have limited usefulness.
Recommended treatment consists of the following: Hypotension, symptomatic: Intravenous fluids, Intravenous Dopamine or Dobutamine, Calcium Gluconate, Isoproterenol, Metaraminol, or Norepinephrine should be used as appropriate; Tachycardia, rapid ventricular rate in patients with antegrade conduction in atrial flutter fibrillation, and accessory pathway with Wolff-Parkinson-White or Lown-Ganong-Levine syndrome- Direct-current cardioversion or intravenous Lidocaine, or intravenous Procainamide.
Intravenous fluids given by slow-drip; Bradycardia, rarely second or third degree atrioventricular (AV) block, with few patients progressing to asystole Intravenous Atropine, Isoproterenol, Norepinephrine, or Calcium chloride, or use of electronic cardiac pacemaker as appropriate.
Specific treatment: Supportive care: Patients in whom intentional overdose is confirmed or suspected should be referred for psychiatric consultation.
Monitoring: Patients with suspected calcium-channel blocker overdose should be placed on a cardiac monitor. Monitor hemodynamic status closely including heart rate blood pressure, EKG, and urinary output.
Monitor electrolytes, renal function tests and glucose. Swan Ganz monitoring may help guide fluid and hemodynamic management.
Monitor respiratory function and oxygenation; pulmonary edema may occur.
Calcium antagonist dosage forms are generally radiolucent. Sustained-release forms may be an exception.
Qualitative and/or quantitative serum levels for calcium antagonists are not readily available, predictive of toxicity, nor helpful in directing therapy.
Except under special circumstances, this medication should not be used when the following medical problems exist: Severe hypotension.
Risk-benefit should he considered when the following medical problem exist: Aortic stenosis, severe (increased risk of heart failure when a Calcium-channel blocking agent is initiated, because of fixed impedance to flow across aortic valve.
Bradycardia, extreme or heart failure (because these agents have slight negative inotropic effect, cautions is recommended).
Hepatic functional impairment (clearance and duration of effect may be prolonged).
Sensitivity to the Calcium-channel blocking agent prescribed.
Special Precautions
Carcinogenicity/Mutagenicity: No evidence of carcinogenicity was found in rats or mice given dosages of 0.5, 1.25, and 2.5 mg per kg of body weight (mg/kg) per day for 2 years. No mutagenicity was found in studies at either the gene or chromosome level.
Pharmacogenetic differences with Amlodipine: In clinical trials there was a greater incidence of edema, flushing and palpitations seen in women than in men.
Dental: Gingival enlargement is a rare side effect that has been reported with Amlodipine, Diltiazem, Felodipine, Nifedipine, and Verapamil. It usually starts as gingivitis or gum inflammation in the first 1 to 9 months of treatment. A strictly enforced program of teeth cleaning by a professional combined with plaque control by the patient will minimize growth rate and severity of gingival enlargement. Periodontal surgery may be indicated in some cases, and should be followed careful plaque control to inhibit recurrence of gum enlargement.
Use in Children: Although appropriate studies on the relationship of age to the effects of Calcium-channel blocking agents have not been performed in the pediatric population, pediatrics-specific problems that would limit the usefulness of Calcium-channel blocking agents in children are not expected.
Use in Elderly: Due to a decreased clearance of Amlodipine with a resulting increase in AUC of 40 to 60%, a lower initial dose may be required.
Use In Pregnancy & Lactation
Fertility: No effects were seen on the fertility of rats treated with Amlodipine at doses up to 10 mg per kg per day, which represents 8 times the maximum recommended human dose.
Pregnancy: Adequate and well-controlled studies have not been done in humans. No evidence of teratogenicity or other embryo/fetal toxicity was observed in rats or rabbits given up to 10 mg/kg during periods of major organogenesis. However, in rats the number of intrauterine deaths increased about five-fold, and little size was significantly decreased by 50%.
Side Effects
Those indicating need for medical attention: Incidence more frequent: Peripheral edema.
Incidence less frequent: Allergic reactions (skin rash).
Incidence rare: Angina; Arrythmias, including Torsades de Pointes; Bradycardia; Extrapyramidal effects, parkinsonian; Gingival enlargement; Hypotension; Mental depression; Tachycardia; Thrombocytopenia.
Those indicating need for medical attention only if they continue or are bothersome: Incidence more frequent: Headache.
Incidence less frequent: Dizziness or lightheadedness; Flushing and feeling of warmth; Nausea; Unusual tiredness or weakness.
Incidence rare: Constipation, diarrhea; Dry mouth; Increased appetite and/or weight gain.
Drug Interactions
Note: Combinations containing any of the following medications, depending on the amount present, may also interact with this medication.
Hydrocarbon inhalation anesthetics; Nonsteroidal Anti-inflammatory Drugs (NSAIDs), especially Indomethacin; Beta-adrenergic blocking agents; Estrogens; Highly protein-bound medications, such as: Anticonvulsants (Hydantoin), Anticoagulants (Coumarin- and Indandione-derivative), Quinine, Salicylates, Sulfinpyrazone; other hypotension-producing medications; Lithium; Sympathomimetics.
Store at temperatures not exceeding 30°C.
ATC Classification
C08CA01 - amlodipine ; Belongs to the class of dihydropyridine derivative selective calcium-channel blockers with mainly vascular effects. Used in the treatment of cardiovascular diseases.
Tab 5 mg x 10 x 10's. 10 mg x 10 x 10's.
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