Formulary
Isoflurane: Indications, Dosing, Side Effects and Interactions
Isoflurane clinical drug profile including indications, dosing, side effects, cautions and interactions.
MedNext Academy | 3 min read
Isoflurane: Indications, Dosing, Side Effects and Interactions
Isoflurane clinical drug profile including indications, dosing, side effects, cautions and interactions.
Indications and dose
**Induction of anaesthesia (in oxygen or nitrous oxide-oxygen)**
- **Adult** (By Inhalation): Initially 0.5 %, increased to 3 %, adjusted according to response, administered using specifically calibrated vaporiser.
**Maintenance of anaesthesia (in nitrous oxide-oxygen)**
- **Adult** (By Inhalation): 1-2.5 %, to be administered using specifically calibrated vaporiser; an additional 0.5-1% may be required when given with oxygen alone.
**Maintenance of anaesthesia in caesarean section (in nitrous oxide-oxygen)**
- **Adult** (By Inhalation): 0.5-0.75 %, to be administered using specifically calibrated vaporiser.
**Induction of anaesthesia (in oxygen or nitrous oxide-oxygen) (but indication not recommended in infants and children of all ages) for isoflurane**
- **Neonate** (By inhalation): Initially 0.5 %, increased to 3 %, adjusted according to response, administered using specifically calibrated vaporiser.
- **Child** (By inhalation): Initially 0.5 %, increased to 3 %, adjusted according to response, administered using specifically calibrated vaporiser.
**Maintenance of anaesthesia (in nitrous oxide-oxygen) for isoflurane**
- **Neonate** (By inhalation): 1-2.5 %, to be administered using specifically calibrated vaporiser; an additional 0.5-1% may be required when given with oxygen alone.
- **Child** (By inhalation): 1-2.5 %, to be administered using specifically calibrated vaporiser; an additional 0.5-1% may be required when given with oxygen alone.
**Maintenance of anaesthesia in caesarean section (in nitrous oxide-oxygen) for isoflurane**
- **Child** (By inhalation): 0.5-0.75 %, to be administered using specifically calibrated vaporiser.
Cautions
For all volatile halogenated anaesthetics Can trigger malignant hyperthermia; raised intracranial pressure (can increase cerebrospinal pressure)
Contraindications
For all volatile halogenated anaesthetics Susceptibility to malignant hyperthermia
Side effects
For all volatile halogenated anaesthetics Common or very common Agitation; apnoea; arrhythmias; chills; cough; dizziness; headache; hypersalivation; hypertension; hypotension; nausea; respiratory disorders; vomiting Uncommon Hypoxia Frequency not known Breath holding; cardiac arrest; haemorrhage; hepatic disorders; hyperkalaemia; malignant hyperthermia; QT interval prolongation; rhabdomyolysis; seizure Side-effects For isoflurane Frequency not known Carboxyhaemoglobinaemia; chest discomfort; cognitive impairment; delirium; dyspnoea; ileus; mood altered (that can last several days); myoglobinuria; skin reactions
Interactions
**Severe interactions:**
- Treatment with isoniazid should be suspended one week before the operation and should not be resumed until 15 days afterwards.
**Other interactions (7):**
- The simultaneous administration of isoflurane and the following products requires strict supervision of the clinical and biological condition of the patient; Combinations advised against: -...
- Combinations requiring precautions in using: - Beta-blockers: Concomitant use of beta blockers may exaggerate the cardiovascular effects of inhalational anesthetics, including hypotension and...
- The action of beta-blockers can be suppressed during the operation with the use of beta-sympathomimetic agents.
- In general, any medication with a beta-blocker need not be stopped and an abrupt reduction of the dosage should be avoided.
- It suffices to inform the anaesthetist about it.
- The disappearance of the myoneural effect takes longer with isoflurane than with other conventional anaesthetics.
Pregnancy
May depress neonatal respiration if used during delivery.
Breast feeding
Breast-feeding can be resumed as soon as mother has recovered sufficiently from anaesthesia.
Medicinal forms
Clinical governance
**Author:** MedNext Clinical Team. **Clinical reviewer:** Dr Shameer Deen, MBBS, MS, MRCS. **Sources:** BNF, Indian Pharmacopoeia, CIMS India. **Correction:** Report errors at support@mednext.academy.
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