Day: June 4, 2016

Mexiletine Its activity is similar to Lidocaine. It is used as local anesthetic as well as anti-arrhythmic by oral route. It belongs to the class 1B anti-arrhythmic drugs. It slows down conduction in heart and makes the heart tissue less sensitive. It has sodium channel blocking property and decrease action potential frequency by lengthening the…

ProcainamideIt is amide derivative of the local anaesthetic procaine which was found to have antiarrhythmic activity but was not suitable clinically due to rapid hydrolysis and marked C.N.S. effects. It inhibits sodium channel and prolongs the cardiac action potential. Restrict entry of sodium and block outward potassium current. Indications:  Premature ventricular contraction & Tachycardia, cardiac…

Amiodarone Amiodarone is come under Class III antiarrhythmic drugs. It is used in various types of cardiac dysrhythmias. It prolongs phase 3 of the cardiac action potential, the repolarization phase where there is normally decreased calcium permeability and increased potassium permeability. At SA and AV nodes, it shows beta blocker like and potassium channel and…

Verapamil The antihypertensive effect of verapamil stems from a decrease in peripheral vascular resistance without an increase in heart rate as a reflex response. It has a marked antiarrhythmic effect. Mode of Action:  Verapamil is a calcium channel blocker which acts by blocking voltage dependent calcium channels in all cases. It is a class IV…

Terazosin Terazosin is an alpha adrenergic blocker. It works by blocking the alpha adrenergic receptors on smooth muscle of the bladder and blood vessels. Terazosin relaxes veins and arteries so blood can pass easily. It also relaxes prostate and bladder neck muscles. Indications:  Mild to moderate hypertension, symptomatic relief of urinary obstruction in patients with…

Indapamide It is a vasodilator & diuretic related to thiazides. It reduces BP at doses which cause little or no diuresis. It molecule contains both polar sulfamoyl chlorobenzamide moiety and a lipid-soluble methylindoline moiety. It acts probably by interfering with ionic fluxes, including that of ca++ across vascular smooth muscle cells. Indications:  Hypertension etc. Side…

Prazosin Prazosin is an alpha adrenergic blocker. Alpha receptors are responsible for the vasoconstriction action of norepinephrine. It works by causing relax to the blood vessel and muscles around the urethra. This mechanism lower down the blood pressure and improve urinary symptoms associated with enlargement of the prostate. Indications:  Moderately potent antihypertensive, CHF & for…

Methyldopa It is moderate efficacy antihypertensive; primarily decreases total peripheral resistance with little effect on cardiac output.Methyldopa is a competitive inhibitor of the enzyme aromatic L-amino acid decarboxylase (DOPA decarboxylase) which is responsible for conversion of L-Dopa into dopamine.It is also converted α-methylnorepinephrine by dopamine β-hydroxylase. Indication:  Mild to moderate hypertension etc. Side Effects:  Sedation,…

Reserpine Vesicular monoamine transporter (VMAT) transports free intracellular norepinephrine, serotonin and dopamine in the presynaptic nerve terminal into presynaptic vesicles. Reserpine irreversibly blocks this VMAT. Reserpine is rauwolfia alkaloid which helps in reducing blood pressure and decrease agitation in patients who have certain mental problems. Indications:  Hypertension, hypertensive emergencies, and toxaemia of pregnancy etc. Side…

DihydralazineIt is directly acting arteriolar vasodilator with little action on venous capacitance vessels. It acts by relaxing smooth muscles used to treat hypertension. It acts as vasodilator primarily in arteries and arterioles. Hydralazine activates potassium channel on vascular smooth muscle through binding at site. This prevents calcium-mediated activation and constriction of the smooth muscle. Indications: …