Table 1 Properties of main anaesthetic agents used in preclinical research: halothane and isoflurane
Agents | Advantages | Disadvantages | Dosing |
|---|---|---|---|
Halothane | Potent anaesthetic | Highly metabolised (hepatotoxic) | Induction 3% to 4% Maintenance 1% to 2% (rats and mice) |
| Â | High therapeutic index | Cardiovascular depressant | Â |
| Â | Rapid induction and recovery (1 to 3 min) | Moderate hypotension: reduction in cardiac output and peripheral vasodilatation) | Â |
| Â | Adequate muscle relaxation | Respiratory depressant | Â |
| Â | Non-irritant, non-flammable nor explosive | Halothane sensitises the heart to catecholamines (sympathetic stimulation) | Â |
| Â | Easy to vaporise | Â | Â |
Isoflurane | Similar physical properties to halothane | Decreases arterial blood pressure (vasodilatation) | Induction 3% to 4% (rats and mice) Maintenance: 1.5% to 2% (mice)1.5% to 2.5% (rats) |
| Â | Rapid induction and recovery | More expensive than halothane | Â |
| Â | Low toxicity and metabolic activity: highly safe | Strong smell: aversive | Â |
| Â | Suitable for high frequency and long-term anaesthesia | More potent respiratory depressant than halothane | Â |
| Â | Minimal cardiovascular depression | Â | Â |
| Â | Moderate respiratory depression | Â | Â |
| Â | Good muscle relaxation | Â | Â |