Propranolol is a non-selective beta blocker mainly used in the treatment of hypertension. It was the first successful beta blocker developed. It is the only drug proven effective for the prophylaxis of migraines in children.
Pharmacokinetics : Propranolol competitively blocks β1- and β2-receptors resulting to decreased heart rate myocardial contractility, BP and myocardial oxygen demand. It only possesses membrane-stabilising properties.
Propranolol information from Drugs Update
Almost completely absorbed from the GI tract (oral); peak plasma concentrations after1 hour.
Distribution : Crosses the blood-brain barrier and placenta, enters breast milk. Protein-binding - 90%.
Metabolism : Hepatic; yields 4-hydroxypropranolol (biologically active).
Excretion : Via urine (as metabolites and small amounts of unchanged drug); 3-6 hours (elimination half-life). May be removed by dialysis.
Propranolol Adverse Reactions / Propranolol Side Effects : Cold extremities, insomnia, fatigue, dizziness, vivid dreams, lassitude, nausea, constipation or diarrhoea, vomiting, anorexia, stomach discomfort, impotence. Weakness, paraesthesia, wheezing, pharyngitis, bronchospasm. CNS disturbances at higher doses and mood alterations. Thrombocytopenic purpura, agranulocytosis, nonthrombocytopenic purpura, thrombocytopenia. Depression, confusion, cognitive dysfunction, emotional lability, fatigue, hallucinations.
Potentially Fatal : Heart failure, heart block and bronchospasm.
Overdosage : Severe and occasionally fatal CV depression.
Special Precautions : Compensated heart failure, peripheral vascular disease, diabetes. Switching from conventional to sustained-release preparations, elderly. Ischaemic heart disease, congestive cardiac failure, renal or hepatic dysfunction. Increased risk of bradycardia and hypotension in patients with underlying cardiac disorders. 1st degree heart block. May mask symptoms of hyperthyroidism and hypoglycaemia. May unmask myasthenia gravis. Abrupt withdrawal may lead to angina, MI, ventricular arrhythmias and death. Lactation.
Other Drug Interactions :
Decreased effect with aluminum and calcium salts, NSAIDs, ampicillin, rifampicin. Concurrent use with chlorpromazine results in raised blood levels of both drugs and additive hypotensive effect. Hypotensive effect reduced by indometacin. Additive effect with other antihypertensives and diuretics. May reduce the clearance of bupivacaine. Plasma levels may be increased by hydralazine and propafenone. Increased serum levels of thioridazine when used with propranolol.
Potentially Fatal : Marked hypertension and bradycardia with adrenaline. Rebound hypertension due to abrupt withdrawal of clonidine is potentiated. Severe bradycardia may occur with digitalis.
Prophylaxis of migraine
List of Contraindications :
Category C: Either studies in animals have revealed adverse effects on the foetus (teratogenic or embryocidal or other) and there are no controlled studies in women or studies in women and animals are not available. Drugs should be given only if the potential benefit justifies the potential risk to the foetus.
In 2nd & 3rd trimesters.
Category D : There is positive evidence of human foetal risk, but the benefits from use in pregnant women may be acceptable despite the risk (e.g., if the drug is needed in a life-threatening situation or for a serious disease for which safer drugs cannot be used or are ineffective).
Propranolol and Lactation : Caution when used during lactation
Propranolol and Geriatic :In general, dose selection for an elderly patient should be cautious, usually starting at the low end of the dosing range, reflecting the greater frequency of the decreased hepatic, renal or cardiac function, and of concomitant disease or other drug therapy.
Propranolol and Other Contraindications : Sinus bradycardia, cardiogenic shock, pulmonary oedema, severe hyperactive airway disease, compensated cardiac failure, Raynaud's disease, hypoglycaemia, severe haemorrhage, metabolic acidosis, severe peripheral arterial disease, 2nd or 3rd degree heart block. Pregnancy (2nd and 3rd trimesters).
Flunarizine is a drug classified as a calcium channel blocker. Flunarizine is a selective calcium entry blocker with calmodulin binding properties and histamine H1 blocking activity. It is effective in the prophylaxis of migraine, occlusive peripheral vascular disease, vertigo of central and peripheral origin, and as an adjuvant in the therapy of epilepsy. It may help to reduce the severity and duration of attacks of paralysis associated with the more serious form of alternating hemiplegia.
Pharmacokinetics : Flunarizine has H1-receptor blocking action and calcium-channel blocking effect. It has also been used as an adjunct epileptic therapy for patients refractory to standard treatment regimens.
Absorption : Absorbed well from the GI tract (oral).
Flunarizine Adverse Reactions / Flunarizine Side Effects : Drowsiness. Rarely wt gain, headache, depression, gastric pain, dry mouth, insomnia, extrapyramidal reactions, galactorrhoea.
Special Precautions : Driving or operating machinery, epilepsy, elderly, CVS disease, glaucoma.
Other Drug Interactions : Plasma levels reduced by phenytoin, carbamazepine, valproic acid.
Food(before/after) : May be taken with or without food
List of Contraindications