BACTHECAL

What it is

BACTHECAL contains baclofen, a gamma-aminobutyric acid derivative, as a racaemic mixture of the R(-) and S(+) isomers. The registered variants are intrathecal solutions for injection available in three strengths: 0.05 mg/1 mL, 10 mg/5 mL, and 10 mg/20 mL.

Approved indications

BACTHECAL is indicated for suppression of voluntary muscle spasm in multiple sclerosis and spinal lesions of traumatic, infectious, degenerative, neoplastic and unknown origin that cause skeletal hypertonus and spastic and dyssynergic bladder dysfunction.

Dosing overview

Treatment with BACTHECAL should always be started in hospital, using small doses which are then gradually increased in a stepwise manner. The optimum daily dosage should be individualised so that clonus, flexor and extensor spasms, and spasticity are reduced, at the same time retaining enough muscle tone to permit active movements and avoiding adverse effects as far as possible. Discontinuation of treatment should always be gradual by successively reducing the dosage over a period of approximately 1 to 2 weeks, except in overdose-related emergencies, or where serious adverse effects have occurred.

Key safety warnings

Patients with psychotic disorders, schizophrenia, depressive or manic disorders or confusional states should be treated cautiously with BACTHECAL and kept under careful surveillance. Suicide and suicide-related events have been reported in patients treated with baclofen, particularly in those with additional risk factors such as alcohol use disorder, depression and a history of previous suicide attempts. Close supervision is essential for patients with additional suicide risk factors. Caution is needed in patients with epilepsy or other convulsive conditions, cortical or subcortical brain damage or significant EEG abnormalities, since baclofen may cause deterioration of seizure control and EEG changes and may precipitate convulsions. Cases of encephalopathy have been reported in patients treated with BACTHECAL, with symptoms including somnolence, depressed level of consciousness, confusion, myoclonus and coma which are usually reversible after treatment discontinuation. If any signs or symptoms of encephalopathy are observed, baclofen should be discontinued. Cases of misuse, abuse and dependence have been reported with baclofen. Caution should be exercised in patients with a history of substance abuse and the patient should be monitored for symptoms of baclofen misuse, abuse or dependence, including dose escalation, drug-seeking behaviour and development of tolerance.

Contraindications

BACTHECAL is contraindicated in patients with known hypersensitivity to baclofen or to any of the components of the formulation.

PBS listing

BACTHECAL intrathecal injection 10 mg in 5 mL is listed on the PBS with 2 items under streamlined restriction. The ex-manufacturer price is A$76.27.

Regulatory history

BACTHECAL intrathecal solutions were first listed on the ARTG on 7 August 2015.