Actiblok-50 IPR Tab

Uses of Actiblok-50 IPR Tab

Metoprolol, which is the generic form of Lopressor is not only used to treat hypertension (high blood pressure), but may also assist in the prevention of strokes, heart attacks and kidney problems.

Side Effects of Actiblok-50 IPR Tab

Dizziness, insomnia, tiredness, headache, vertigo, confusion, bradycardia, shortness of breath, hypotension, Raynaud's phenomenon, CHF, peripheral oedema, cold extremities, syncope, chest pain, palpitations, gangrene, claudication, hallucinations, nightmares, visual disturbances; diarrhoea, constipation, flatulence, GI pain, heartburn, nausea, hiccups, xerostomia; bronchoconstriction, wheezing, dyspnoea; dry skin, maculopapular, psoriasiform, pruritus, worsening of psoriasis, urticarial rash. Rarely, Peyronie's disease, tinnitus, restless legs, musculoskeletal pain, a polymyalgia such as syndrome, decreased libido, blurred vision, dry mucous membranes, sweating; reversible alopecia, thrombocytopenia, agranulocytosis, retroperitoneal fibrosis, wt gain, arthritis, dry eyes.

Drug Interactions

Additive effect w/ catecholamine-depleting drugs (e.g. reserpine) and MAOIs. May antagonise β1-adrenergic stimulating effects of sympathomimetics. Additive negative effects on SA or AV nodal conduction w/ cardiac glycosides, nondihydropyridine Ca channel blockers. Paradoxical response to epinephrine may occur. Increased plasma concentrations w/ CYP2D6 inhibitors (e.g. bupropion, cimetidine). Increased risk of hypotension and heart failure w/ myocardial depressant general anaesth (e.g. diethyl ether). Risk of pulmonary HTN w/ vasodilators (e.g. hydralazine) in uraemic patients. Reduced plasma levels w/ rifampicin. May increase negative inotropic and negative dromotropic effect of antiarrhythmic drugs (e.g. quinidine, amiodarone). May reduce antihypertensive efficacy w/ indometacin. May increase effects of hypoglycaemics.

Contraindications

2nd or 3rd degree AV block, sick sinus syndrome, hypotension, decompensated heart failure, sinus bradycardia, severe peripheral arterial circulatory disorders, cardiogenic shock, severe asthma and bronchospasm, untreated phaeochromocytoma, Prinzmetal's angina, metabolic acidosis.

Mechanism of Action

Metoprolol selectively inhibits β1-adrenergic receptors but has little or no effect on β2-receptors except in high doses. It does not exhibit membrane stabilising or intrinsic sympathomimetic activity. Onset: 1-2 hr (oral); 20 min, when infused over 10 min (IV). Duration: Oral: Approx 3-6 hr (immediate release); approx 24 hr (extended release). IV: 5-8 hr. Absorption: Absorbed readily and completely from the GI tract. Bioavailability increased by food. Bioavailability: Approx 50%. Time to peak plasma concentration: Approx 1.5-2 hr (oral). Distribution: Widely distributed, enters breast milk, crosses the placenta and blood-brain barrier. Volume of distribution: 3.2-5.6 L/kg. Plasma protein binding: Approx 12%. Metabolism: Extensively hepatic via CYP2D6 isoenzyme and undergoes oxidative deamination, O-dealkylation followed by oxidation and aliphatic hydroxylation. Excretion: Via urine (as metabolites and unchanged drug). Elimination half-life: 3-4 hr (fast hydroxylators); approx 7 hr (poor hydroxylators).

Special Precautions

Patients w/ myasthenia gravis, well-compensated heart failure, bronchospastic disease, AV conduction disorders, substantial cardiomegaly. May mask signs and symptoms of hyperthyroidism and hypoglycaemia. Patients w/ history of cardiac failure or those w/ minimal cardiac reserve. Patients undergoing major surgery involving general anaesth. Avoid abrupt withdrawal as it may precipitate thyroid storm or MI, and may exacerbate angina and ventricular arrhythmias. Hepatic impairment. Pregnancy and lactation. Patient Counselling May affect ability to drive or operate machinery. Monitoring Parameters Monitor BP, ECG and heart rate.

How to Use

Take orally with food and water, as directed by your physician.

How to Store

Keep in a cool, dry place away from sunlight and moisture.

Safety Concerns

• Alcohol: Avoid during treatment.
• Breastfeeding: Not recommended.
• Pregnancy: Contraindicated.
• Liver/Kidney: Use with caution.

Content Disclaimer

This content is for educational purposes only. Please consult your doctor before use.