Medical, Drugs, Pharmaceuticals And Diseases Information

QUINIDINE:  It is an alkaloid from Cinchona bark-the dextroisomer of quinine & has been noted to suppress ‘rebellious palpitation.’ Quinidine increases threshold for excitation and reduces conduction velocity, thus limits the spread of arrhythmia. Quinidine is used to treat  Atrial fibrillation or flutter, paroxysmal supra ventricular tachycardia. Ventricular prema¬ture beats & ventricular tachycardia. Maintenance of sinus rhythm following electro conversion.

Dosage : 200-300 mg 3-4 times daily. Initially give test dose.

Contra indications of  quinidine:  It Not recommended for children and Myasthenia gravis.  Intolerance or idiosyncrasy to quinidine, heart block, C.H.F. and hypo-tensive states.  History of embolism. Special Precautions:   Renal dysfunctions. Paediatric:

Quinidine is Not recommended in Pregnancy: No serious effect reported. Lactation: Not recommended. Elderly: Reduced dosage necessary. Side-effects:  Higher doses can cause A.V. dissociation, nausea, vomiting, diarrhoea, cinchonism (ringing in ear, deafness, vertigo, headache, visual disturbances),, angioedema, asthma & vascular collapse. Drug Interactions:  Cimetidine, erythromycin inhibits the hepatic metabolism of quinidine, interaction with beta-blockers causes sinus bradycardia. Amiodarone may increase the plasma concentration of quinidine. Phenobarbitone and rifampicin decreases its effects.  Hyperkalemia increases effect of quinidine.

Metolazone is a diuretic with actions and uses similar to those of the thiazide diuretics even though it does not contain a thiazide ring system. Metalazone is available under brand names  Zaroxolyn and Mykrox. It is mainly  used to treat congestive heart failure and high blood pressure.

Metolazone is used in the treatment edema,  including that associated with heart failure and for hypertension. For edema usual dose is 5 to 10mg, in some cases doses of 20mg or more but nor more than 80mg to be given in 24 hrs.For  Hypertension:- 2.5 to 5 mg daily either alone or with other anti hypertensives.

Metolazone aggravates  hypersensitivity to other thiazides and sulfonamide derivatives. It is contraindicated in  anuria, hepatic coma, severe renal and hepatic dysfunction, refractory hypokalaemia, hyponatraemia, hypercalcaemia, symptomatic hyperuricaemia and Addison’s disease.

Metolazone  Drug Interactions: In drugs like Furosemide, ACE inhibitors and  glibendamide. Preacaustiosn should be taken while using Metolazone in cases of  Diabetes mellitus; gout; electrolyte,disturbances; lupus erythematosus; hepatic and renal impairment;

Side effects on using Metolazone (zaroxolyn ) include dizziness, headache, or heart arrhythmias (palpitations).The  Serious, though rare, side effects include aplastic anemia, pancreatitis, agranulocytosis, and angioedema. Metolazone, like other thiazide diuretics, may unmask latent diabetes mellitus or exacerbate gout, especially by interacting with medicines used to treat gout.

Nebivolol available from Mylan Laboratories under brand name Nebilet is a lipophilic beta 1 blocker drug . It exerts its actions by exhibiting a high selectivity for p-adrenergic receptors and also by reducing the peripheral vascular resistance by modulating NO release. It is devoid of intrinsic sympathomimetic or membrane stabilizing activity but appears to have nitric oxide-mediated vasodilator effects.

Nebivolol is used mainly for hypertension and high blood pressure. Dosage is typically 5mg once daily taken with or without food, preferably at a fixed time in a day. A reduced starting dose of 2.5mg (with upward titration where necessary) is recommended in the elderly and in patients with renal insufficiency.

Contraindications of Nebivolol: Use of the drug in children and patients with hepatic insufficiency is not recommended. Side-effects of Nebivolol include Headache, fatigue, paraesthesias and dizziness.

Carvedilol –brand name Coreg and Coreg CR is an arylethanolamine nonspecific fl-adrenoreceptor antagonist with beta blocking activity. It is a beta blocker group of drugs having anti hypertension effect partly by reducing total peripheral resistance and vasodilatation. It blocks adreno receptors and inhibits J-adreno receptor-mediated compensatory mechanisms.

Carvedilol is widely used for the treatment of hypertension and congestive heart failure.
Dosage for hypertension is initially 6.25 mg twice daily. If tolerated well after 7-14 days, increase to 12.5mg twice daily if needed. If needed again increase the dose up to 25 mg twice daily, after 7-14 days. Maximum total daily dose is 50mg.

In case of congestive heart failure start the dosage with 3.125 mg twice daily for 2 weeks. If tolerated raise to 6.25mg twice daily and then double the dose every 2 weeks to the level tolerated by patients. Maximum dose is 25mg and 50mg for patients weighing less than 85 kgs and more than 85 kgs respectively.

Contraindications of Carvedilol include hypersensitivity; Patients with NYHA class IV decompensated cardiac failure requiring IV inotropic therapy, bronchial asthma, second or third-degree AV block, Sick Sinus syndrome, cardiogenic shock or severe bradycardia, severe hepatic impairment and lactation.

Special Precautions: Before starting the Carvedilol treatment, laboratory confirmation of liver injury is very much essential. Abrupt withdrawal of 3-blockers may result in exacerbation of the symptoms of hyperthyroidism. During the initiation of therapy, avoid driving or operating machinery. Safety of Carvedilol is not established during pregnancy. as well as in Children. Side effects of Carvedilol include increased sweating, fatigue, oedema, bradycardia, hypotension (including postural), hyperglycaemia, hypercholesterolemia, bronchitis, insomnia, impotency, skin reactions, tinnitus, anaemia and even sudden death.

Drug interactions of Carvedilol: Rifampicin decrease while cimetidine increase the AUC & Cmax of carvedilol. Increase in Steady-state AUC and trough concentration of digoxin. Catecholamine-depleting agents & beta-receptors blockers results in hypotension or severe bradycardia.

Esmolol drip is a cardiovascular system medicine used in the treatment of Supraventricular, tachycardia, perioperative tachycardia and hypertension. It is rapid Acting Blood Pressure Medicine

Esmolol hcl is a beta 1-selective (cardioselective) adrenergic receptor blocking agent available under brand name of Brevibloc. It can rapidly control ventricular rate.

The normal dosage is 500 mcg/kg/min for 1 min, in case of Perioptachy-1000 meg/kg within 30 sees. Maintenance - for SVT & perioptachycardia: Initiate with 50 mcg/kg/min for 4 mins increasing maximum up to 300 mcg/kg/min. Every increment of 50 meg/ kg/min in maintenance should be preceded by the same loading dose.

Contra indication of Esmolol includes sinus bradycardia, heart block, cardiogenic shock or overt heart failure. Special precaution has to be taken for use in pregnancy, nursing mothers, and in children. Side effects of esmolol include hypotension, dizziness, headache, confusion, fatigue, paresthesia, asthenia, depression, anxiety, anorexia and bronchospasm. No significant drug interaction is seen with with digoxin, warfarin and morphine.

Bisoprolol available under brand name  Zabeta is a beta blocker drug for the treatment in cardiovascular system. It is a competitive antagonist of the beta-adrenergic receptors. It has high beta, selectivity. There is no membrane-stabilizing or partial agonist action. The reduction in heart rate and blood pressure action lasts for 24 hrs. Bisoprolol is used in the treatment of Hypertension and Coronary artery disease.

Dosage of Bisoprolol starts at 2.5 or 5mg/day and build up to10 -20mg/day.Dose reduction is done in case of severe renal impairment.

Centra-Indications of Bisoprolol include: Bradycardia, second or third degree heart block, conduction abnormalities, congestive heart failure, chronic obstructive pulmonary disease, peripheral vascular insufficiency, pregnancy and lactation.

Special precautions: while administering Bisoprolol should be taken in case of poor L.V function, bronchial asthma, diabetes, thyrotoxicosis, M.I, severe renal impairment and abrupt withdrawal. Bisoprolol is not recommended for children and is not recommended in pregnancy as safety is not established. During lactation it has to be used with caution also caustion advised for elderly.
.
Side effects of Bisoprolol include giddiness, headache, fatigue, bradycardia, nausea, dyspnoea, sleep disturbances, cold extremities, and reduced libido.

Drug Interactions of Bisoprolol: It enhances the action of anesthetic agents, clonidine, calcium antagonists,    hypoglycemic agents & NSAIDs. Rifampicin cause
Reduction in plasma concentration & elimination.

Labetalol is a beta blocker group of drugs and is unique among adrenergic blockers as it blocks the adregenic receptors thereby decreasing blood pressure, heart beat rate and vascular resistance. Labetalol   is   orally   effective   and   undergoes considerable first pass metabolism.

Labetalol is used for treatment of all grades of hypertension and especially useful in pheochromocytoma and clonidine withdrawal hypertension.

The typical dosage can be started with 50mg twice daily and increased at fortnightly intervals to 100-200mg twice daily. Usual dose being  labetalol 400 mg daily for those with predisposition to  bronchospasm,   right ventricular   failure, and secondary   to   pulmonary  hypertension.  Special precautions to be taken while using labetalol in cases of sinus bradycardia shock, pregnancy, lactation and anesthesia with agents producing myocardial depression.  Common side effects of labetalol include abrupt withdrawal, diabetes, cardiac failure, hyperthyroidism, postural hypotension, eye and skin reaction, liver dysfunction, failure of ejaculation in males, headache, angina, jaundice, dreams, nightmares.

The commonly available brand names of Labetalol are Normodyne and  Trandate.