Treatment of hypertension

Treatment of hypertension

• 1.
  Drugs used forthe treatment of Hypertension Dr. Pravin Prasad M.B.B.S., MD Clinical Pharmacology Lecturer, Lumbini Medical College 1 March, 2019 (17 Falgun 2075), Friday
• 2.
  By the endof the class BSN 1st year students will be able to: Classify drugs used for the treatment of hypertension Explain the mechanism of action, indications and adverse effects of: Furosemide and Hydrochlorothiazide Amlodipine Captopril Losartan
• 3.
  Hypertension Most common CardiovascularDisease Effects of raised Blood Pressure  Kidney  renal faiure  Heart  coronary diseases  Brain  stroke
• 4.
  Hypertension Types:  Essential/Primary, and Secondary Diagnosis:  Repeated, reproducible measurements of elevated blood pressure
• 5.
  Normal Regulation ofBlood Pressure Blood Pressure = Cardiac Output x Peripheral Vascular Resistance Kidney also involved in regulation of BP Local regulation of BP also seen Mechanism: Neural: Baroreflexes via autonomic nerves Humoral: Renin-Angiotensin-Aldosterone system
• 6.
  Anti-Hypertensive Drugs: Classification Diuretics Hydrochlorthiazide, Furosemide Sympathoplegics Clonidine,Labetalol, Prazosin, Propranolol Direct Vasodilators Amlodipine, Sodium nitroprusside, hydralazine Agents that block production or action of angiotensin Enalapril, Losartan, Spironolactone
• 7.
  Diuretics: Mechanism of Action Furosemide Hydrochlorothiazide
• 8.
  Diuretics: Mechanism of Action Inhibitsspecific transporters in nephrons Furosemide: Na+-K+-2Cl- cotransport Hydrochlorothiazide: Na+-Cl- symport Inhibition leads to: Decreased Na+ and Cl- absorption More Na+, Cl- and water passed in urine
• 9.
  Diuretics: Mechanism of Action Furosemide: Highamount of urine formed (brisk diuresis occurs) •Blood volume decreases leading to decreased in cardiac output Hydrochlorothiazide: Small persisting Na+ and volume deficit  slow development of reduction in PVR (arterioles) •Decreased stiffness of wall vessel
• 10.
  Diuretics: Uses Furosemide: Hypertension complicatedby: •Chronic renal failure, refractory Congestive Heart Failure •Resistant to combination regime containing thiazide Hydrochlorothiazide: Mild anti-hypertensive In combination with other anti-hypertensives •Potentiates other anti-hypertensives
• 11.
  Diuretics: Adverse effects Hydrochlorothiazide:Hypokalaemia Furosemide: Acute Saline Depletion Hyperglycaemia, Hyperlipidaemia GIT: Nausea/Vomiting, Diarrhoea CNS: Headache, Giddiness, Weakness, Paresthesia Allergic reactions
• 12.
  Calcium channel blockers Amlodipine,Nifedipine, Felodipine, Nitrendipine, Cilnidipine Verapamil, Diltiazem: not commonly used Acts by blocking calcium channels present in smooth muscles of blood vessels Leads to vasodilatation and decrease in blood pressure Amlodipine: long acting (administered once a day)
• 13.
  Amlodipine: Uses First linedrug for hypertension Monotherapy Combination therapy with other anti- hypertensives Angina pectoris Stable angina
• 14.
  Amlodipine: adverse effects Ankleoedema Palpitation, Flushing Hypotension Headache, drowsiness Nausea, abdominal pain, worsening of gastro- Esophageal reflux Skin rashes
• 15.
  ACE inhibitors Includes: Captopril, Enalapril,Fosinopril, Ramipril Acts by inhibiting Angiotensin Converting Enzyme Hence called ACE inhibitors Angiotensin-I cannot be converted to Angiotensin-II (A-II) Effects of A-II not seen
• 16.
  Captopril: Uses Hypertension Monotherapy Combination therapy Congestiveheart failure Left ventricular dysfunction after myocardial infarction Diabetic nephropathy
• 17.
  Captopril: Adverse effects Drycough, Dysguesia Hyperkalaemia Angioedema Skin rash Hypotension Palpitation, tachycardia Should not be administered in pregnancy
• 18.
  Angiotensin Receptor Blockers Includes: Losartan, Valsartan,Telmisartan, Olmesartan Acts by blocking Angiotensin receptors (AT1) Effects of A-II blocked •Vasodilation •Decreased central and peripheral sympathetic stimulation •Decreased aldosterone release
• 19.
  Losartan: Uses andAdverse effects Uses: Hypertension Myocardial infarction Diabetic nephropathy Adverse effects: Hypotension, hyperkalaemia Angioedema Headache, dizziness, weakness
• 20.
  Conclusion Blood pressure canbe controlled by multiple ways Hydrochlorothiazide acts by creating small Na+ deficit Amlodipine acts by causing relaxation of blood vessels Captopril inhibits angiotensin converting enzymes and decrease availability of angiotensin-II
• 21.
  Any queries? Next class: Drugsused in angina and heart failure Thank you.