Morphine On Smooth Muscle

Morphine activates receptors on the smooth muscle of the stomach antrum and of both large and small bowel, causing it to contract. Peristalsis propulsion is reduced and segmentation increased. Thus, although morphine 'stimulates' smooth muscle, delayed gastric emptying and constipation occur, with gut muscle in a state of tonic contraction. Delay in the passage of the intestinal contents results in greater absorption of water and increased viscosity of faeces, which contribute...

Advantages And Disadvantages Of Parenteral Administration

An i.v. bolus, i.e. rapid injection, passes round the circulation being progressively diluted each time it is delivered principally to the organs with high blood flow brain, liver, heart, lung, kidneys . Advantages are that the i.v. route gives swift, effective and highly predictable blood concentration and allows rapid modification of dose, i.e. immediate cessation of administration is possible if unwanted effects occur during administration. The route is suitable for administration of drugs...

Advantages And Disadvantages Of Enteral Administration

For systemic effect Advantages are convenience and acceptability. Disadvantages are that absorption may be delayed, reduced or even enhanced after food or slow or irregular after drugs that inhibit gut motility antimuscarinic, opioid . Differences in presystemic elimination are a cause of variation in drug effect between patients. Some drugs are not absorbed gentamicin and some drugs are destroyed in the gut insulin, oxytocin, some penicillins . Tablets taken with too small a quantity of liquid...

Drugs used in hypertension and angina

Two groups of drugs, (3-adrenergic blockers and calcium channel blockers, are used in both hypertension and angina. Several drugs for hypertension are used also in the treatment of heart failure. Diuretics, particularly the thiazides, are useful antihypertensives. They cause an initial loss of sodium with a parallel contraction of the blood and extracellular fluid volume. The effect may reach 10 of total body sodium but it is not maintained. After several months of treatment, the main blood...