📋 Indications & Clinical Dosage
*Hypertension:*
ORAL: Adult& Children above 12yrs: 25-50 mg daily, higher doses are rarely necessary
*Angina:*
ORAL: Adult: 100 mg daily in 1-2 divided doses
*Arrhythmias:*
ORAL: Adult & Children above 12yrs: 50-100 mg daily
BY IV INJ: Adult: 2.5 mg every 5 min (max. per dose 10 mg), repeated if necessary, given at a rate of 1mg/min
BY IV INF: Adult: 150 mcg/kg every 12 hrs if required, to be given over 20 min
*Migraine prophylaxis (an unlicensed indication):*
ORAL: Adult: 50-200 mg daily in divided doses
*Early intervention within 12 hours of myocardial infarction:*
BY IV INJ: Adult: Initially 5 mg, to be given over 5 min, followed by (oral) 50 mg after 15 min, then (oral) 50 mg after 12 hours, then (oral)100 mg daily.
⛔ Contraindications
3rd or 3rd degree AV block (without pacemaker), severe bradycardia, sick sinus syndrome, un-controlled heart failure, cardiogenic shock, severe peripheral arterial disease, hypotension, metabolic acidosis, untreated pheochromocytoma, severe asthma or CO
⚠️ Precautions & Warnings
AV block, heart failure (avoid if un-controlled), peripheral arterial circulatory disorders (avoid if severe), Prinzmetals angina, myasthenia gravis, Ischaemic heart disease, withdraw gradually, history of bronchospasm, diabetes, hyperthyroidism, renal or hepatic impairment, psoriasis, elderly, consider withdrawal before elective surgery, anaphylaxis risk due to increased sensitivity to allergens, Always withdraw gradually over period of 1-2 weeks IV administration requires cardiac and blood pressure monitoring.
Dose adjustment in renal impairment: with oral use max 50mg daily if eGFR15-35 ml/minute/1.73m2; max 25mg daily or 50 mg on alternate days if eGFR less than 15 ml/minute/1.73m2.With intravenous use max 10 mg on alternate days if eGFR15-35 ml/minute/1.73m2; max.10 mg every 4 days if eGFR less than 15 ml/minute/1.73m2.
🔄 Drug Interactions
Ca+antagonists, antihypertensives including centrally acting agents (e.g. clonidine), antiarrhythmics, antipsychotics, TCADs, MAOls, fluvoxamine, barbiturates, cardiac glycosides, sympathpmimetics, cimetidine, hydralazine, rifampicin, insulin/oral hypoglycaemics, NSAIDs, ergot derivatives, erythromycin, anaesthetics, diuretics.
⚠️ Adverse Reactions / Side Effects
Cardiovascular effects including bradycardia, postural hypotension, increased AV block, cardiac arrhythmias, Raynauds phenomenon cold extremities, sexual dysfunction, GI, sleep and CNS disturbances, dyspnoea rarely, bronchospasm, skin reactions, withdraw if unexplained dry eyes or rash, fatigue, paraes-thesia, peripheral neuropathy, arthralgia, myopathy, altered blood sugar, haematology and lipid levels. Rare: heart failure.
🤰 Pregnancy & Lactation Safety
Pregnancy Risk:
Use only when no safer alternative exists for a serious problem.
Lactation / Breastfeeding:
Caution advised
🧪 Compatibility & Storage Stability
Compatibility: Stable in NS, D5W.
Stability & Storage: Protect from light.
📚 Official Regulatory & Clinical References
- Drug Regulatory Authority of Pakistan (DRAP): Drug Registration, S.R.O. Price Gazettes & National Essential Medicines List (NEML).
- World Health Organization (WHO): Collaborating Centre for Drug Statistics Methodology (ATC/DDD Index).
- Formulary Standards: British National Formulary (BNF) & Pakistan National Formulary (PNF) guidelines.