Drugs	Mechanism Of Action	Adverse Effects	Contraindications	Uses
Directly acting vasodilators	Venous	Nitrates (GTN and Nitroglycerin)	Releases NO through cyclic GMP	Tachycardia, headache, flushing and orthostatic hypotension	As they decrease preload do not use in inferior MI or right ventricular infarction	Acute and chronic angina
	Arterial	CCB (DHP like Amlodipine and non-DHP like Verapamil)	Blocks calcium channels in the cardiac and smooth muscle	Gingival hyperplasia and peripheral edema, AV block, bradycardia and constipation	Hypotension and hypersensitivity	HTN, arrythmia, angina
		Minoxidil, Diazoxide	ATP sensitive potassium channel openers	Hypertrichosis, Fluid retention		Alopecia
		Prazosin	Alpha Blocker	First dose hypotension	CHF	3rd line drug in HTN
		Hydralazine	Directly relaxes arteriolar smooth muscles through cyclic AMP	Tachycardia, fluid retention and SLE	CAD, angina, RHD as it causes compensatory tacchycardia	PIH
	Mixed	ACE inhibitors	Prevent conversion of Angiotensin I to II	Dry cough hyperkalemia and hypotension	Pregnancy and hereditary angioedema	Heart failure, HTN, MI, CCF, Scleroderma crisis
		ARB	Prevents Angiotensin II from binding to its receptor (cardio-reno protective)	Hyperkalemia and hypotension	Pregnancy
		Sodium Nitroprusside	Both venous and arteriolar dilator releasing NO	Cyanide toxicity		Hypertensive emergencies
Beta 2 receptor agonist		Salbutamol Terbutaline	Beta 2 mediated vasodilatation	Tremors hypokalemia
Centrally acting Alpha 2 receptor agonist		Clonidine, Methyldopa	Acts on presynaptic alpha 2 receptor and decreases sympathetic outflow	Rebound hypertension on withdrawal		Clonidine - Last Drug Of Choice In HTN Methyldopa - First drug of choice in PIH but nowadays we are into “Nifedipine Retard or Labetelol”
Endothelin receptor antagonists		Bosentan, Ambrisentan	ETA and ETB receptor blocker	Anaemia, teratogenecity		Pulmonary arterial hypertension
Beta Blockers with Nitric Oxide vasodilatation		Bisoprolol, Nebivolol	Beta 1 block reduces heart rate and cardiac work load and NO causes vasodilatation	Bradycardia	Heart Block	Young hypertensives