📋 Indications & Clinical Dosage
*Hypertension, Angina:*
Adult: 5-10 mg tab once daily; max. 20 mg per day
*Adjunct in heart failure:*
Adult: Initially 1.25 mg tab once daily for 1 week, dose to be taken in the morning, then increased if tolerated to 2.5 mg once daily for 1 week, then increased to 3.75 mg once daily for 1 week, then increased to 5 mg once daily for 4 weeks, then increased to 7.5 mg once daily for4 weeks, then increased to 10 mg once daily; max 10 mg per day.
Children: Not recommended.
⛔ Contraindications
Acute or decompensated heart failure requiring intravenous inotropes, sino-atrial block, 2nd or 3rd degree AV block (without pacemaker), severe bradycardia, uncontrolled heart failure, cardiogenic shock, severe peripheral arterial disease, hypotension, metabolic acidosis, untreated pheochromocytoma, severe asthma or COPD.
⚠️ 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 agent (e.g. clonidine), antiarrhythmics, antipsychotics, TCADs, MAOIs, fluvoxamine, barbiturates, cardiac glycosides, sympathomimetics, 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 upset, sleep and CNS disturbances, skin reactions, fatigue, paraesthesia, peripheral neuropathy, arthralgia, myopathy, altered blood sugar haematology and lipid levels. Withdraw if unexplained dry eyes or rash. Rare: Heart failure, dyspnea, bronchospasm
🤰 Pregnancy & Lactation Safety
Pregnancy Risk:
Avoid, risk cannot be ruled out.
Lactation / Breastfeeding:
Caution advised
📚 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.