Download Ebook PDF Rapid clinical pharmacology
Download Ebook PDF Rapid clinical pharmacology Full 146 page – Download medical books free
This pocket reference guide is a must for all medical students andjunior doctors preparing for exams in pharmacology or needing arapid reminder during a clinical attachment.
In light of the growing pressures on those who prescribe drugsto patients, increasing emphasis has been placed on the importanceof pharmacology in the undergraduate medical curriculum. Rapid Clinical Pharmacology, with its concise,easy–to–use approach, offers an appealing format for students touse in both clinical practice and exam preparation and its one–page per drug/class′ layout easily facilitates thegeneration of a personal student formulary.
Each chapter of the book mirrors each section of the BNF toallow easy cross–referencing and then each chapter is divided intoconsistent sections as per other books in the Rapid series.
Rapid Clinical Pharmacology will also be availableas a mobile application for iPhone, iPod Touch, iPad andBlackberry. See wiley.com/go/mededapps for further details.
Histamine type 2 receptor antagonists
EXAMPLES Ranitidine, cimetidine
MECHANISM OF ACTION Competitive inhibitors of all histamine type 2 receptors. Inhibit histamine- and gastrin-stimulated gastric acid secretion by their action on parietal cells in the stomach.
. Gastric and duodenal ulcers
. Gastro-oesophageal reﬂux
. Treatment and prophylaxis of NSAID-associated ulcers CAUTIONS AND CONTRA-INDICATIONS
. If red ﬂag features of malignancy, need to investigate prior to initiating treatment SIDE-EFFECTS
. GI disturbance, especially diarrhoea
. Gynaecomastia (cimetidine)
METABOLISM AND HALF-LIFE These drugs are excreted largely unchanged in urine. t½ is 2–3 h.
MONITORING No speciﬁc drug monitoring required.
. Cimetidine inhibits Cytochrome P450 activity in the liver and therefore potentiates the
action of drugs such as warfarin, phenytoin and theophylline
. Ranitidine can be used prior to general anaesthesia in patients at high risk of aspiration
particularly in obstetric practice (Mendelson’s syndrome)
MECHANISM OF ACTION
Bulk laxatives (e.g. ispaghula husk) – polysaccharide polymers that are not broken down bydigestion and thereby increase stool volume. This stimulates intestinal peristalsis (via the
stretch reﬂex) as well as softening faeces.
Osmotic laxatives (e.g. lactulose, Movicol) – these poorly absorbed solutes increase thevolume of water in the bowel lumen by osmosis hence increasing transit.
Stimulant laxatives (e.g. senna, docusate sodium) – the primary effect is via direct stimulation of myenteric plexus resulting in smooth muscle contraction and increased peristalsis.
Faecal softeners (e.g. arachis oil) – these are surfactants that reduce surface tension and allowwater to penetrate and soften faeces.
. Hepatic encephalopathy (lactulose) CAUTIONS AND CONTRA-INDICATIONS
. Bowel obstruction
. Galactosaemia (lactulose only)
. Acute inﬂammatory bowel disease
. Severe dehydration SIDE-EFFECTS
. Abdominal cramps
. Electrolyte disturbances
METABOLISMAND HALF-LIFE Variable – most are broken down locally in the GI tract with minimal absorption.MONITORING No speciﬁc drug monitoring required.
. Lactulose may enhance warfarin effects in severe liver disease IMPORTANT POINTS
. Before prescribing a laxative ensure constipation is not secondary to an underlying pathology such as bowel cancer
. It requires at least 2–3 days for osmotic or bulking laxatives to take full effect
. Avoid laxatives if bowel obstruction is suspected due to risk of perforation
. Lactulose reduces ammonia-producing organisms and is used in the treatment of hepatic encephalopathy
. Chronic laxative use can cause tolerance (stimulant laxatives)