BNF for Children (BNFC) 2018-2019

Related drugs

Other drugs used for Cerebral palsy and spasticity: co-

careldopa p. 257 , dantrolene sodium p. 821.

Useful Resources

Cerebral palsy in under 25 s: assessment and management.

National Institute for Health and Care Excellence. Clinical

guideline 62. January 2017.

http://www.nice.org.uk/guidance/NG 62

Spasticity in under 19 s: management. National Institute

for Health and Care Excellence. Clinical guideline 145 .July

2012 (updated November 2016 ).

http://www.nice.org.uk/guidance/CG 145

3.1 Dystonias and other

involuntary movements

Dystonias and related disorders

Dystonias

Dystonias may result from conditions such as cerebral palsy

or may be related to a deficiency of the neurotransmitter

dopamine as in Segawa syndrome.

Dopaminergic drugs used in dystonias

Levodopa, the amino-acid precursor of dopamine, acts by

replenishing depleted striatal dopamine. It is given with an

extracerebraldopa-decarboxylase inhibitor, which reduces

the peripheral conversion of levodopa to dopamine, thereby

limiting side-effects such as nausea, vomiting, and

cardiovascular effects; additionally, effective brain-

dopamine concentrations are achieved with lower doses of

levodopa. The extracerebral dopa-decarboxylase inhibitor

most commonly used in children is carbidopa (in co-

careldopa p. 257 ).

Levodopa therapy should be initiated at a low dose and

increased in small steps; thefinal dose should be as low as

possible. Intervals between doses should be chosen to suit

the needs of the individual child.

In severe dystonias related to cerebral palsy, improvement

can be expected within 2 weeks. Children with Segawa

syndrome are particularly sensitive to levodopa; they may

even become symptom free on small doses. Levodopa also

has a role in treating metabolic disorders such as defects in

tetrahydrobiopterin synthesis and dihydrobiopterin

reductase deficiency. Tetrahydrobiopterin may have a role in

metabolic disorders.

Children may experience nausea within 2 hours of taking a

dose; nausea and vomiting with co-careldopa is rarely dose-

limiting.

In dystonic cerebral palsy, treatment with larger doses of

levodopa is associated with the development of potentially

troublesome motor complications (including response

fluctuations and dyskinesias). Responsefluctuations are

characterised by large variations in motor performance, with

normal function during the‘on’period, and weakness and

restricted mobility during the‘off’period.

Antimuscarinic drugs used in dystonias

The antimuscarinic drugs procyclidine hydrochloride below

and trihexyphenidyl hydrochloride p. 257 reduce the

symptoms of dystonias, including those induced by

antipsychotic drugs; there is no justification for giving them

routinely in the absence of dystonic symptoms. Tardive

dyskinesia is not improved by antimuscarinic drugs and may

be made worse.

There are no important differences between the

antimuscarinic drugs, but some children tolerate one better

than another.

Procyclidine hydrochloride can be given parenterally and

is effective emergency treatment for acute drug-induced

dystonic reactions.

If treatment with an antimuscarinic is ineffective,

intravenous diazepam p. 220 can be given for life-

threatening acute drug-induced dystonic reactions.

Drugs used in essential tremor, chorea, tics, and

related disorders

Haloperidol p. 245 can also improve motor tics and

symptoms of Tourette syndrome and related choreas. Other

treatments for Tourette syndrome include pimozide p. 247

[unlicensed indication] (important: ECG monitoring

required), and sulpiride p. 247 [unlicensed indication].

Propranolol hydrochloride p. 104 or another beta-

adrenoceptor blocking drug may be useful in treating

essential tremor or tremor associated with anxiety or

thyrotoxicosis.

Botulinum toxin type A p. 258 should be used under

specialist supervision. Treatment with botulinum toxin type

A can be considered after an acquired non-progressive brain

injury if rapid-onset spasticity causes postural or functional

difficulties, and in children with spasticity in whom focal

dystonia causes postural or functional difficulties or pain.

Other drugs used for Dystonias and other involuntary

movementsTrifluoperazine, p. 248

ANTIMUSCARINICS

Procyclidine hydrochloride

lDRUG ACTIONProcyclidine exerts its antiparkinsonian

action by reducing the effects of the relative central

cholinergic excess that occurs as a result of dopamine

deficiency.

lINDICATIONS AND DOSE

Acute dystonia

▶BY INTRAMUSCULAR INJECTION, OR BY INTRAVENOUS

INJECTION

▶Child 1 month–1 year: 0. 5 – 2 mg for 1 dose, dose usually

effective in 5 – 10 minutes but may need 30 minutes for

relief

▶Child 2–9 years: 2 – 5 mg for 1 dose, dose usually

effective in 5 – 10 minutes but may need 30 minutes for

relief

▶Child 10–17 years: 5 – 10 mg, occasionally, more than

10 mg, dose usually effective in 5 – 10 minutes but may

need 30 minutes for relief

Dystonia

▶BY MOUTH

▶Child 7–11 years: 1. 25 mg 3 times a day

▶Child 12–17 years: 2. 5 mg 3 times a day

lUNLICENSED USENot licensed for use in children.

lCONTRA-INDICATIONSGastro-intestinal obstruction.

myasthenia gravis

lCAUTIONSCardiovascular disease.hypertension.liable to

abuse.psychotic disorders.pyrexia.those susceptible to

angle-closure glaucoma

lINTERACTIONS→Appendix 1 : procyclidine

lSIDE-EFFECTS

▶Common or very commonConstipation.dry mouth.

urinary retention.vision blurred

▶UncommonAnxiety.cognitive impairment.confusion.

dizziness.gingivitis.hallucination.memory loss.nausea.

rash.vomiting

256 Movement disorders BNFC 2018 – 2019

Nervous system

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