Durasalyn-CR

Durasalyn-CR

Manufacturer:

Raptakos, Brett

Distributor:

KMT
Full Prescribing Info
Contents
Theophylline, salbutamol sulfate.
Description
Each capsule contains anhydrous theophylline 200 mg and salbutamol sulfate equivalent to salbutamol 4 mg. It also contains neutral seeds, ethyl cellulose, talc, colloidal silicon dioxide, shellac, isopropyl alcohol and dewaxed shellac as excipients.
Action
Pharmacology: Theophylline (3,7-dihydro-1,3-dimethyl-1-H-purine-2,6-dione) is a xanthine bronchodilator.
Theophylline directly relaxes the smooth muscle of the bronchial airway and pulmonary blood vessels; increases diaphragmatic contractility. Theophylline is also a central respiratory stimulant.
Mechanism of Action: Main mechanism of action of xanthines is inhibition of phosphodiesterase, which results in an increase in cyclic adenosine monophosphate (cAMP).
Other Effects: Inhibition of extracellular adenosine (which causes bronchoconstriction), stimulation of endogenous catecholamines, antagonism of prostaglandins, PGE2 and PGF2, direct effect on mobilization of intracellular calcium resulting in smooth muscle relaxation and β-adrenergic agonist activity on the airways.
Salbutamol [1-(4-(RS)-hydroxy-3 hydromethylphenyl)2-(t-butylamino) ethanol] is a selective β2-adrenoceptor agonist with effects on smooth and skeletal muscle. These include bronchodilation, relaxation of uterine muscle and antiallergic effect. Smooth muscle relaxation is thought to occur via the adenyl cyclase-cyclic adenosine monophosphate (cAMP) system.
Pharmacokinetics: Absorption: Theophylline is completely absorbed after oral administration.
Metabolism and Excretion: Xanthines are biotransformed in the liver (85-90%) to 1,3-dimethyluric acid, 3 methylxanthine and 1-methyluric acid. Excretion is by the kidneys: <15% of the drug is excreted unchanged.
Salbutamol is well absorbed from the GIT. The proportion of circulating drug that is protein bound is approximately 10%. Transfer of the drug across the placenta has been demonstrated both in vitro and in vivo.
Indications/Uses
Relief and prevention of reversible bronchoconstriction in COPD and in the treatment of refractory bronchial asthma.
Dosage/Direction for Use
1 cap twice daily preferably at 8 pm and 8 am.
Overdosage
Symptoms: Theophylline: Anorexia, nausea, vomiting, nervousness, insomnia, agitation, irritability, headache, tachycardia, extrasystoles, tachypnea, tonic/clonic convulsions.
Treatment: If Seizure has not Occurred: Induce vomiting, even if emesis has occurred spontaneously. However, do not induce emesis in patients with impaired consciousness.
If Seizure Occurs: Establish an airway and administer oxygen. Administer IV diazepam 0.1-0.3 mg/kg up to 10 mg. Monitor vital signs, maintain blood pressure and provide adequate hydration.
Post-Seizure Coma: Maintain airway and oxygenation. Perform intubation and lavage instead of inducing emesis. Introduce the cathartic and activated charcoal via a large bore gastric lavage tube. Provide full supportive care and adequate hydration while the drug is metabolized. If repeated oral activated charcoal is inactive, charcoal hemoperfusion may be indicated.
The expected symptoms with overdosage of salbutamol are those of excessive β-stimulation and/or occurrence or exaggeration of any of the symptoms (see Adverse Reactions) eg, seizures, angina, hypertension or hypotension, tachycardia, arrhythmias, nervousness, headache, tremor, dry mouth, palpitation, nausea, dizziness, fatigue, malaise and insomnia. Hypokalemia may also occur.
Treatment consists of discontinuation of salbutamol together with appropriate symptomatic therapy.
Contraindications
Hypersensitivity to any xanthine, peptic ulcer, underlying seizure disorders (unless receiving appropriate anticonvulsant medication) and patients with history of hypersensitivity to salbutamol.
Warnings
Status asthmaticus is a medical emergency and is not rapidly responsive to usual doses of conventional bronchodilators. Oral theophylline products alone are not appropriate for status asthmaticus.
Toxicity: Excessive doses may cause severe toxicity. Incidence of toxicity increased significantly at serum levels >20 mcg/mL. Serum levels >20 mcg/mL are rarely found after appropriate administration of recommended doses. However, in patients in whom theophylline plasma clearance is reduced for any reason (eg, hepatic function impairment; patients >55 years, particularly males and those with chronic lung disease; cardiac failure and sustained high fever), even conventional doses may result in increased serum levels and potential toxicity. Serious side effects eg, ventricular arrhythmias, convulsions or even death may appear as the 1st sign of toxicity (eg, nausea, restlessness) may occur frequently when initiating therapy, but are usually transient when such signs are persistent during maintenance therapy. They are often associated with serum concentrations >20 mcg/mL.
Cardiac Effects: Theophylline may cause dysrhythmias or worsen preexisting arrhythmias. Any significant change in cardiac rate or rhythm warrants monitoring and further investigation.
General: Immediate hypersensitivity reactions may occur after administration of salbutamol as demonstrated by rare cases of urticaria, angioedema, rash and oropharyngeal edema. Salbutamol can produce a significant cardiovascular effect in some patients as measured by pulse rate, blood pressure symptoms and/or electrocardiographic changes.
Special Precautions
Theophylline should not be administered concomitantly with other xanthines. Use with caution in patients with hypoxemia, hypertension, cardiac disease, congestive heart failure, alcoholism, elderly patients and patients with a history of peptic ulcer.
Theophylline may occasionally act as a local irritant to the gastrointestinal tract. Symptoms are more commonly centrally mediated and associated with serum drug concentrations >20 mcg/mL.
Salbutamol should be used with caution in patients with cardiovascular disorders, especially coronary insufficiency, cardiac arrhythmias and hypertension; in patients with convulsive disorders, hyperthyroidism or diabetes mellitus.
Use in pregnancy: It is not known whether theophylline can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. There are no adequate and well-controlled studies in pregnant women. Theophylline should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
Use in lactation: Theophylline is distributed into breast milk and may cause irritability or other signs of toxicity in nursing infants. Because of the potential for serious adverse reactions in nursing infants from theophylline, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.
Use in children: Safety and effectiveness in children <12 years have not been established with Durasalyn-CR.
Use In Pregnancy & Lactation
Use in pregnancy: It is not known whether theophylline can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. There are no adequate and well-controlled studies in pregnant women. Theophylline should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
Use in lactation: Theophylline is distributed into breast milk and may cause irritability or other signs of toxicity in nursing infants. Because of the potential for serious adverse reactions in nursing infants from theophylline, a decision should be made whether to discontinue nursing or to discontinue the drug, taking into account the importance of the drug to the mother.
Adverse Reactions
Adverse reactions/toxicity are uncommon at serum theophylline levels <20 mcg/mL. The most consistent adverse reactions are due to overdosages.
Gastrointestinal: Nausea, vomiting, epigastric pain, diarrhoea.
Central Nervous System: Headache, irritability, insomnia, muscle twitching, clonic and tonic generalized convulsions.
Cardiovascular System: Palpitation, tachycardia, extrasystoles, flushing, hypotension, ventricular arrhythmias.
Respiratory: Tachypnoea.
Renal: Potentiation of diuresis.
Others: Alopecia, rash.
Salbutamol is generally well tolerated and serious toxic effects are few. The adverse reactions to salbutamol are similar in nature to reactions to other sympathomimetic agents, although the incidence of certain cardiovascular effects is lower with salbutamol. The most frequent adverse reactions to salbutamol are nervousness and tremor. Other reported reactions are headache, tachycardia and palpitations, muscle cramps, insomnia, nausea, weakness and dizziness. Rare cases of urticaria, angioedema, rash and oropharyngeal edema have been reported after the use of salbutamol. The reactions are generally transient in nature and it is usually not necessary to discontinue treatment with salbutamol.
Drug Interactions
The following drug interactions have been demonstrated with theophylline. Agents that decrease theophylline levels include barbiturates, charcoal, ketoconazole, rifampicin, smoking and sulfinpyrazone. Agents that increase theophylline levels include allopurinol, β-blockers (nonselective), calcium-channel blockers, cimetidine, oral contraceptives, corticosteroids, disulfiram, ephedrine, interferon, macrolides and quinolones.
The concomitant use of salbutamol and other oral sympathomimetic agents is not recommended since such combined use may lead to deleterious cardiovascular effects. Salbutamol should be administered with extreme caution to patients being treated with monoamine oxidase inhibitors or tricyclic antidepressants because the action of salbutamol on the vascular system may be potentiated. β-receptor-blocking agents and salbutamol inhibit the effect of each other.
Storage
Store at temperatures not exceeding 30°C.
ATC Classification
R03DB04 - theophylline and adrenergics ; Belongs to the class of xanthines and adrenergics. Used in the systemic treatment of obstructive airway diseases.
Presentation/Packing
Controlled-release cap 10 x 10's.
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