POSITIVE INOTROPIC DRUGS
Positive inotropic drugs increase the force of contraction of the myocardium.
1. Cardiac glycosides: Cardiac glycosides are most useful in the treatment of supraventricular tachycardias, especially for controlling ventricular response in persistent atrial fibrillation.
-Digoxin: indicated for heart failure and supraventricular arrhtythmias (Lanoxin).
-Digitoxin: same indications as digoxin.
-Digoxin-specific antibody: indicated for the treatment of known or strongly suspected digoxin or digitoxin overdosage. (Digibind).
2. Phosphodiesterase inhibitors:
-Enoximone: indicated for congestive heart failure where cardiac output reduced and filling pressures increased. (Perfan).
-Milrinone: for short-term treatment of severe congestive heart failure unresponsive to conventional maintenance therapy and acute heart failure, including low output states following heart surgery (Primacor).
OEDEMA
Oedema is the medical term for fluid retention in the body.
The build-up of fluid causes affected tissue to become swollen. The swelling can occur in one particular part of the body – for example, as the result of an injury – or it can be more general.
This is usually the case with oedema that occurs as a result of certain health conditions, such as heart failure or kidney failure.
As well as swelling or puffiness of the skin, oedema can also cause:
-skin discolouration
-areas of skin that temporarily hold the imprint of your finger when pressed (known as pitting oedema)
-aching, tender limbs
-stiff joints
-weight gain or weight loss
-raised blood pressure and pulse rate.
Types of oedema
Oedema can occur anywhere in the body, but it's most common in the feet and ankles. This is known asperipheral oedema.
Other types of oedema include:
-cerebral oedema – affecting the brain
-pulmonary oedema – affecting the lungs
-macular oedema – affecting the eyes.
Idiopathic oedema is a term used to describe cases of oedema where a cause can't be found.
Causes
It's normal to have some swelling in your legs at the end of the day, particularly if you've been sitting or standing for long periods, inmobility and standing for long periods are the most common causes of oedema in the legs.
Oedema is often a symptom of an underlying health condition. It can occur as a result of the following conditions or treatments:
-pregnancy
-kidney, chronic lung, thyroid or liver disease
-heart failure
-malnutrition
-medication, such as corticosteroids, medicine for hypertension or the contraceptive pill.
Other possible causes include: a blood clot, severe varicose veins, a leg injury or leg surgery, burns to the skin.
Treatment
Oedema usually clears up by itself. However, your GP may suggest some self-help measures to reduce fluid retention, such as:
-losing weight (if you're overweight)
-taking regular exercise.
-raising your legs three to four times a day to improve your circulation
-avoiding standing for long periods of time
If an underlying condition is causing the fluid imbalance, it should clear up after the condition has been diagnosed and treated.
DIURETICS
1. Thiazides and related diuretics:
-Bendroflumethiazide: indicated for oedema and hypertension.
-Chlortalidone: indicated for ascites due to cirrhosis in stable patients, oedema due to nephrotic syndrome, hypertension, mild to moderate chronic heart failure and diabetes insipidus. (Hygroton).
-Cyclopenthiazide: indicated for oedema, hypertension and heart failure. (Navidrex).
-Indapamide: indicated for essential hypertension. (Natrilix, Ethibide).
-Metolazone: for oedema and hypertension. (Metenix).
-Xipamide: for oedema and hypertension. (Diurexan).
2. Loop diuretics:
-Furosemide: indicated for oedema and resistant hypertension. (Lasix).
-Bumetanide: indicated for oedema. (Burinex).
-Torasemide: for oedema and hypertension.(Torem).
3. Potassium-sparing diuretics and aldosterone antagonists:
Potassium-sparing diuretics:
-Amiloride hydrochloride: indicated for oedema and potassium conservation when used as an adjunt to thiazide or loop diuretics for hypertension, congestive heart failure or hepatic cirrhosis with ascites.
-Triamterene: indicated for oedema and potassium conservation with thiazide and loop diuretics. (Ditac).
Aldosterone antagonists:
-Eplerenone: adjunt in stable patients with left ventricular dysfunction with evidence of heart failure, following myocardial infraction. (Inspra).
-Spironolactone: for oedema and ascites in cirrhosis of the liver, malignant ascites, nephrotic sydrome, congestive heart failure and primary hyperaldosteronism. (Aldactone).
4. Potassium-sparing diuretics with other diuretics: the use of this combinations may be justified if compliance is a problem.
-Amiloride with thiazides (Co-amilozide, Navispare).
-Amiloride with loop diuretics (Co-amilofruse, Burinex-A).
-Triamterene with thiazides (Co-triamterzide, Dyazide, Dytide, Kalspare).
-Triamterene with loop diuretics (Frusene).
-Spironolactone with thiazides (Co-flumactone).
-Spironolactone with loop diuretics (Lasilactone).
5. Osmotic diuretics:
-Mannitol: indicated for cerebral oedema and raised intra-ocular pressure, glaucoma.
7. Diuretics with potassium: Centyl, Diumide-k Continus, Neo-NaClex-k).
Sources:
-http://www.nhs.uk/
-BNF 57 March 2009