Classification Based on

a. Chemical structure

I. Sulphonamidcs.and others - c.g.. sulphadiazine. etc.

2. Beta-lactum ring - e.g.. penicillin

3. Tetracycline - e.g.. Oxytetracycline,.doxycycline.etc.

b. Mechanism of action

1. Inhibits cell-wall synthesis - penicillin. cephalosporin..cycloserine. etc.

2. Cause leakage from cell-membrane – polypeptides (polymyxin,  Bacitracin), polyenes (Nystatin)

3. Inhibit protein synthesis - tetracyclines. chloramphenicols. erythromycin.

4. Cause mis-reading of mRNA code - aminoglycosides

5. Interfere with DNA function - refampicin.. metronidazole

6. Interfere with intermediary metabolism - sulphonamides. ethambutole

c. Type of organism against which it is primarily activate

I. Antibacterial - penicillin.

2. Antifungal - nystatin.

d. Spectrum of activity

1. Broad spectrum - tetracylines .

2. Narrow spectrum - penicillin G (penG). streptomycin.erythromycin

e. Type of action

I. Bacteriostatic - sulphonamides, erythromycin.tertracyclines

2. Bacteriocidal - penicillin. aminoglycoside

f. Source

I. Fungi - penicillin. cephalosporins

2. Bacteria - Polymyxin B

VITAMIN -K

• Group of lipophilic, hydrophobic vitamins.
• Needed for the post-translational modification of coagulation proteins.
• Phylloquinone (vitamin K1) is the major dietary form of vitamin K.

• Vitamin K2 (menaquinone, menatetrenone) is produced by bacteria in the intestines.

Stages of anesthesia

Stage I

Analgesia

Still conscious but drowsy

Stage II

Excitement stage

Loss of consciousness, however, irregular ventilation may be present which affects absorption of inhalation agents.

Reflexes may be exaggerated.

This is a very dangerous stage

Stage III

Surgical anesthesia

Loss of spontaneous movement

Regular, shallow respiration

Relaxation of muscles

Stage IV

Medullary paralysis

Death

Halothane (Fluothane) MAC 0.76%, Blood/gas solubility ratio 2.3
- Nonflammable.
- Any depth of anesthesia can be obtained in the absence of hypoxia.
- Halothane produces a marked hypotensive effect 
- accompanies hypotension.
- Halothane “sensitizes” the ventricular conduction system in the heart to the action of catecholamines. However, ventricular arrhythmias are rare if
- respiratory acidosis, hypoxia and other causes of sympathetic stimulation are avoided.
- Respiration is depressed by all anesthetic concentrations.
- Halothane is metabolized to a significant extent and some of its metabolic produces have been shown to be hepatotoxic.
- Can produce a malignant hyperpyrexia due to an uncontrolled hypermetabolic reaction in skeletal muscle. 

Halothane is generally used with nitrous oxide, an opiate and a neuromuscular blocking drug.

EPHEDRINE

It act indirectly and directly on α and β receptors. It increases blood pressure both by peripheral vasoconstriction and by increasing the cardiac output. Ephedrine also relaxes the bronchial smooth muscles.

Ephedrine stimulates CNS and produces restlessness, insomnia, anxiety and tremors.
Ephedrine produces mydriasis on local as well as systemic administration.
Ephedrine is useful for the treatment of chronic and moderate type of bronchial asthma, used as nasal decongestant and as a mydriatic without cycloplegia. It is also useful in preventing ventricular asystole in Stokes Adams syndrome.

Itraconazole:

The drug may be given orally or intravenously.