Special attention must be given to recognizing the signs and symptoms of overdosage, especially during the initial screening and dose- titration phase of treatment, but also during re- introduction of LIORESAL INTRATHECAL after a period of interruption in therapy.
Symptoms of LIORESAL INTRATHECAL Overdose:
Drowsiness, lightheadedness, dizziness, somnolence, respiratory depression, seizures, rostral progression of hypotonia and loss of con- sciousness progressing to coma of up to 72 hr. duration. In most cases reported, coma was reversible without sequelae after drug was discontinued. Symptoms of LIORESAL INTRATHECAL overdose were reported in a sensitive adult patient after receiving a 25 mcg intrathecal bolus.
Treatment Suggestions for Overdose:
There is no specific antidote for treating overdoses of LIORESAL INTRATHECAL (baclofen injection); however, the following steps should ordinarily be undertaken:
- Residual LIORESAL INTRATHECAL solution should be removed from the pump as soon as possible.
- Patients with respiratory depression should be intubated if necessary, until the drug is eliminated.
Anecdotal reports suggest that intravenous physostigmine may reverse central side effects, notably drowsiness and respiratory depression. Caution in administering physostigmine is advised, however, because its use has been associated with the induction of seizures and bradycardia.
Physostigmine Doses for Adult Patients:
Administer 2 mg of physostigmine intramuscularly or intravenously at a slow controlled rate of no more than 1 mg per minute. Dosage may be repeated if life- threatening signs, such as arrhythmia, convulsions or coma occur.
Physostigmine Doses for Pediatric Patients:
Administer 0.02 mg/ kg physostigmine intramuscularly or intravenously, do not give more than 0.5 mg per minute. The dosage may be repeated at 5 to 10 minute intervals until a therapeutic effect is obtained or a maximum dose of 2 mg is attained.
Physostigmine may not be effective in reversing large overdoses and patients may need to be maintained with respiratory support.
If lumbar puncture is not contraindicated, consideration should be given to withdrawing 30- 40 ml of CSF to reduce CSF baclofen concentration.