Baclofen

Indications

Baclofen is used for: Pain, Chronic muscle spasticity, Multiple sclerosis, Spasm, Stiffness, Low back pain

Adult Dose

Oral Spasticity Adult: Initially, 5 mg tid for 3 days increased to 10 mg tid for 3 days, then in similar increments and intervals until either 20 mg tid is reached or until desired effect is obtained. Max: 80 mg daily. Elderly: Initiate with lower doses.

Child Dose

Oral Spasticity Child: 0.75-2 mg/kg daily. May initiate with 2.5 mg 4 times daily, increased gradually every 3 days until desired effect is obtained. Maintenance: 6-10 yr: 30-60 mg daily; 2-6 yr: 20-30 mg daily; 12 mth-2 yr: 10-20 mg daily. Max: >10 yr: 2.5 mg/kg daily.

Renal Dose

Renal impairment: Dose reduction may be required.

Administration

Should be taken with food.

Contra Indications

Hypersensitivity. Active peptic ulcer disease.

Precautions

Cerebrovascular disorders, epilepsy, severe psychotic disorders, confusional states, history of peptic ulcer, resp depression, diabetes (DM), hepatic or renal impairment, elderly, pregnancy. Avoid sudden withdrawal. Lactation: Enters breast milk in small amounts; not recommended

Pregnancy-Lactation

Pregnancy There are no adequate data on the developmental risk associated with the use in pregnant women Oral administration of baclofen to pregnant rats resulted in an increased incidence of fetal structural abnormalities at a dose which was also associated with maternal toxicity Clinical considerations May increase the risk of late-onset neonatal withdrawal symptoms Animal data Baclofen given orally has been shown to increase the incidence of omphaloceles (ventral hernias) in fetuses of rats given ~13 times on a mg/kg basis, or 3 times on a mg/m2 basis, the maximum oral dose recommended for human use; this dose also caused reductions in food intake and weight gain in the dams This abnormality was not seen in mice or rabbits Lactation At recommended oral doses, baclofen is present in human milk There are no human data on the effects of baclofen on milk production There are no adequate data on the effects of baclofen on the breastfed infant Withdrawal symptoms can occur in breastfed infants when maternal administration is stopped, or when breastfeeding is stopped Consider developmental and health benefits of breastfeeding along with the mother’s clinical need and any potential adverse effects on the breastfed infant or from the underlying maternal condition

Interactions

Hypotensive effect may be increased with antihypertensives. Concomittant use with levodopa in Parkinson patients may result in confusion, agitation, hallucinations. Potentially Fatal: CNS depressants and alcohol may potentiate CNS effects.

Adverse Effects

Side effects of Baclofen : >10% Drowsiness, transient (10-63%), Dizziness (5-15%), Nausea (4-12%), Confusion (1-11%) 1-10% Headache (4-8%), Insomnia (2-7%), Constipation (2-6%), Urinary frequency (2-6%), Fatigue (2-4%) <1% Abdominal pain, Ankle edema, Anorexia, Ataxia, Blurred vision, Chest pain, Coordination disorder, Depression, Diarrhea, Dry mouth, Diplopia, Dysarthria, Dyspnea, Dystonia, Enuresis, Euphoria, Excitement, Hallucinations, Hematuria, Hypotension, Impotence, Miosis, Muscle pain, Mydriasis, Nasal congestion, Nocturia, Nystagmus, Palpitation, Paresthesia, Excessive perspiration, Pruritus, Rash, Rigidity, Seizure, Strabismus, Slurred speech, Syncope, Tinnitus, Tremor, Urinary retention, Vomiting, Weight gain Potentially Fatal: Respiratory or CV depression, seizures.

Mechanism of Action

Baclofen is an antispastic. It inhibits both monosynaptic and polysynaptic reflexes at spinal level.