Материал: MasterPass _ Pharmacology in 7 Days for Medical Students

THERAPEUTIC USES AND SIDE EFFECTS

Respiratory depression inducing drugs ‘STOP breathing’:

Sedatives and hypnotics Trimethoprim

Opiates Polymyxins

Lithium: therapeutic uses

1In manic-depressive (bipolar) illness as a mood stabilising agent. Since lithium has a slow onset of action, neuroleptic and/or benzodiazepines are given at the beginning of lithium therapy. During the course of the therapy, antidepressants are often used concomitantly.

2Alcoholism in manic-depressive patients.

3Mania: Lithium is often used as an adjunct to antipsychotic therapy in this condition.

4Recurrent endogenous depression: In this condition, lithium is used as an adjunct to TCAs or SSRI therapy.

5Schizophrenia/schizoaffective disorders.

6Syndrome of inappropriate ADH secretion (SIADH): Lithium is an ADH antagonist and thus can be used in SIADH, although demeclocycline is the drug of choice.

Lithium: side effects

1CNS: Tremors, choreoathetosis, ataxia, increased motor activity, mental confusion, dysarthria and aphasia.

2GIT: N, V, D and anorexia (it is of central origin).

3Renal:

aLoss of ability of collecting tubules to conserve water (under the influence of ADH) → excessive free water clearance → polyuria and polydypsia. This is

called nephrogenic diabetes insipidus. b Chronic interstitial nephritis.

c Minimal change glomerulonephritis (→ nephrotic syndrome).

4Thyroid: Hypothyroidism and enlargement of thyroid gland.

5CVS: Bradyand tachycardia (called ‘sick sinus syndrome’) and T-wave flattening.

6Use in pregnancy: Teratogenic.

7Use in infants: Poor suck and Moro’s reflexes (i.e. ↓ motor activity), hypothermia, hepatomegaly, Na+ retention (→ oedema; weight gain).

8Miscellaneous: Transient acneiform eruptions, folliculitis, leukocytosis, etc.

LITH:

Leukocytosis

Insipidus (diabetes insipidus, tied to polyuria)

Tremors/Teratogenesis

Hypothyroidism

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PHARMACOLOGY IN 7 DAYS FOR MEDICAL STUDENTS

Monoamine oxidase inhibitors (MAOIs): side effects

Restlessness, insomnia, excitement, convulsions, throbbing headache, drowsiness, postural hypotension, atropine-like side effects, weight gain due to an increase in appetite, sexual dysfunctions (impotence) and cheese reaction.

Cheese reaction: Normally, when tyramine containing food stuffs (like cheese, yoghurt, broad beans, red wine, etc.) are taken, tyramine is broken down by intestinal and hepatic monoamine oxidase enzymes (MAO-A and MAO-B). However, on MAOIs administration, MAO enzymes are inhibited so that tyramine is not destroyed and it reaches the systemic circulation. From there, it is actively taken up by the noradrenergic nerve terminals where it displaces noradrenaline from its receptor sites causing marked increase in the intraneuronal concentrations of noradrenaline. This in turn causes spontaneous leakage of increased amounts of noradrenaline into the synaptic cleft that may lead to hypertensive crisis, intracranial haemorrhage, epistaxis or throbbing headache.

Carbamazepine: therapeutic uses

1It is the drug of choice for partial seizures especially temporal lobe epilepsy.

2Grand mal epilepsy.

3Trigeminal neuralgia.

4Bipolar disorder (mania).

Sodium valproate: therapeutic uses

1Epilepsy: Grand mal, petit mal, mixed grand mal-petit mal, absence seizures, partial seizures, secondary generalised tonic clonic seizures, akinetic epilepsy, atonic epilepsy, myoclonic jerks and infantile spasms.

2Resistant manic-depressive (bipolar) illness.

Sodium valproate: side effects

VALPROATE:

Vomiting

Alopecia

Liver toxicity

Pancreatitis/Pancytopenia

Retention of fats (weight gain)

Edema (peripheral oedema)

Appetite increase

Tremor

Enzyme inducer (liver)

Levodopa: therapeutic uses

1Parkinsonism: Levodopa particularly ameliorates bradykinesia. However, it is not curative and responsiveness decreases with time.

2Galactorrhea/hyperprolactinemia.

Bromocriptine: therapeutic uses

1Treatment of Parkinsonism in combination with L-dopa: Bromocriptine is not effective in drug-induced extra-pyramidal symptoms.

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THERAPEUTIC USES AND SIDE EFFECTS

Dose:

•1st week: 1–1.25 mg at night.

•2nd week: 2–2.5 mg at night.

•3rd week: 2.5 mg twice a day.

•4th week: 2.5 mg three times a day.

•Usual therapeutic range 10–30 mg/day in divided doses.

2 For prevention and suppression of lactation in mothers.

3 Treatment of prolactin-secreting pituitary tumour and associated hypogonadism, galactorrhea and infertility.

4 Treatment of growth hormone-secreting pituitary tumour (acromegaly). Physiologically, dopamine inhibits the release of growth hormone.

Bromocriptine: side effects

1GIT: N, V and anorexia.

2CVS: Postural hypotension, tachycardia and cardiac arrhythmias.

3CNS:

4Ergot-related side effects: include pulmonary infiltrates and erythromelalgia (red, swollen and tender feet and hands).

Imipramine: therapeutic uses

1Depression: It is particularly useful in depressed patients with sleep disturbances, poor appetite and weight loss.

2Neurosis associated with depression.

3Nocturnal enuresis and attention-deficit hyperkinetic syndrome in children.

4Pain:

a Unexplained chronic body pains.

b Neuralgias (trigeminal/hypoglossal/herpetic neuralgias).

5Panic and phobic disorders.

6Alcoholism.

7Obsessive compulsive disorders (antipsychotic and antidepressant drugs are given in combination).

8Manic-depressive (bipolar) disorder.

Tricyclic antidepressants (TCA): side effects

1Anticholinergic: Blurring of vision, photophobia, dryness of mouth, metabolic or sourtaste, tachycardia, constipation, and urinary retention.

2Cerebral toxicity: Sedation, lethargy, delirium, confusion, excitement, convulsions, increased frequency of epileptic fits and ataxia.

3Cardiotoxicity: Arrhythmias like AV extrasystole, ventricular tachycardia (VT) and ventricular fibrillation (VF), MI.

4Hypersensitivity/allergic manifestations: Skin rash, agranulocytosis, photosensitivity, cholestatic jaundice and tremors.

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PHARMACOLOGY IN 7 DAYS FOR MEDICAL STUDENTS

TCAS:

Thrombocytopenia

Cardiac (arrhythmia like AV extrasystole, VT, VF, MI)

Anticholinergic

Seizures

Benzylpenicillin: therapeutic uses

1Beta-hemolytic streptococcal infections (acute tonsillitis, pharyngitis, skin and bone infections).

2Staphylococcal infections (only non-beta lactamase producing strains).

3Pneumocccal infections (pneumocccal pneumonia/meningitis).

4Meningococcal meningitis (causative organism: Neisseria menigititis).

5Gonococcal urethritis (causative organism: Neisseria gonorrhea).

6Syphilis (causative organism: Treponema pallidum).

7Anaerobic infections above the diaphragm.

8Actinomycosis.

9Anthrax.

10Erysipeloid.

11Fusospirochetal diseases (like Torch mouth, Vincent’s angina).

12Leptospirosis.

13Listeriosis.

14Pasteurella multocida-induced diseases.

Benzylpenicillin: side effects

1 Allergic reactions include:

a Urticaria, severe pruritus and joint swelling. b Skin rashes of various types.

c Serum sickness-like syndrome.

d Allergic renal disturbances (interstitial nephritis). e Allergic blood dyscrasias (hemolytic anaemia).

f Acute anaphylactic shock.

2Jarisch-Herxhimier reaction: In cases of syphilis, large amounts of toxins and antigens are released when first dose of benzylpenicillin kills the causative organism (treponema pallidum). These toxins and antigens in turn cause worsening of the symptoms (increase in the size of the lesions, malaise and joint pains). This is called Jarisch-Herxhimier reaction.

3Hyperkalemia and hypernatremia in large doses.

4Superadded infection: On oral administration of large doses of benzylpenicillin, these drugs kill normal bacterial flora of the body. This in turn causes growth of opportunistic organisms (e.g. candida albicans, Clostridium difficile, etc.) and may result in superadded infections e.g. pseudomembranous colitis caused by clostridium difficile (treated by metronidazole and vancomycin).

Cephalosporins: therapeutic uses

11st Generation:

•UTI.

•Surgical prophylaxis.

•Minor staphylococcal infections (cellulitis/soft tissue abscesses).

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THERAPEUTIC USES AND SIDE EFFECTS

22nd Generation:

•H. Influenzae infection.

•Morexella catarrhalis infection.

•Sinusitis.

•Otitis media.

•Meningitis.

•Anaerobic (Bacteroides fragilis) infection.

•Peritonitis.

•Diverticulitis.

•Surgical prophylaxis (colorectal surgery, hysterectomy, appendicectomy, etc.).

33rd and 4th Generation:

•Meningitis.

•Febrile neutropenic patients.

•Lyme’s disease.

•Chancroid.

•Gonorrhea.

Cephalosporins: side effects

1Hypersensitivity reactions: These include allergy, anaphylaxis, fever, hemolytic anaemia, granulocytopenia, nephritis and skin rash. Cross-allergy is seen between penicillins and cephalosporins in approximately 5–10% of the patients. Patients with a history of allergy to penicillins should not receive cephalosporins.

2Toxicity: Local irritation with I/M injection; thrombophlebitis with I/V injection;

renal toxicity like interstitial nephritis and tubular necrosis; hypoprothrombinemia; bleeding disorders (when ceftriaxone is administered in a dose of >02 gm/ day for long periods); biliary sludging syndrome (→ cholelithiasis); superadded infections.

Quinolones: therapeutic uses

1st Generation:

1Uncomplicated UTI.

2Resistant bacillary dysentery.

2nd Generation:

1Respiratory tract infections (pneumonias).

2Tuberculosis (as a Second-line agent).

3Typhoid fever.

4Bacterial diarrhoea (e.g. caused by shigella, salmonella, E coli, etc.).

5UTI caused by pseudomonas; chlamydial and gonococcal prostatitis, urethritis and cervicitis.

6Systemic pseudomonas infection.

7Intrabdominal, soft tissue, bone and joint infections.

8Eradication of meningococci from carriers.

9Prophylactically in neutropenic patients.

Quinolones: side effects

1GIT: N, V, D; hepatotoxicity.

2CVS: Prolongation of QT interval.

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