Psychotropic Drugs in Children: Thioridazine (Mellaril)

Optimum Dosage

1-3 mg/kg/day

20-200 mg/day

Not recommended under 2 years of

age

Starting dose 10-25 mg b.i.d.

Drug Interactions

CNS depressants

Antacids decrease absorption

Anticholinergics

Anticonvulsants increase risk of seizures

Epinephrine increases hypotension

Guanethidine

Minor Side-Effects^a

Anticholinergic effects (>30%)

Orthostatic hypotension (10%-30%)

Drowsiness, sedation, lethargy (10%-30%)

Amenorrhea and inhibition of ejaculation (10%-30%)

Tachycardia (2%-10%)

Photosensitivity and skin pigmentation (2%-10%)

Weight gain (10%-30%)

Gastrointestinal distress^c

Nasal stuffiness^c

Breast enlargement and galactorrhea^c

Peripheral edema^c

Parotid swelling^c

Contra-indications

Hypersensitivity to other phenothiazines

History of blood dyscrasias

Do not use in “pure” attention deficit disorders, because of decrease in learning curve

Drug Withdrawal Effects

Tardive and withdrawal dyskinesia following long-term usage (>3-6 months) particularly in non-responders to treatment

Rebound behavioural phenomenon

Gastrointestinal distress

Insomnia, restlessness, irritability

Chills and cold sweats

Common practice to decrease over 1 month to minimize above phenomena

Major Side-Effects

Parkinsonism (2%-10%)^b

Akathisia(2%-10%)^b

Dystonic reactions (<2%)^b

Cardiac arrhythmias (10%-30%)^b

ECG abnormalities without cardiac injury (>30%)

Pigmentary retinopathy (10%-30%) after chronic therapy

Obstructive jaundice (<2%)

Blood dyscrasia (2%-10%) within 1-3 months

Dulling of intellectual performance⁰

Epileptic seizures (<2%)^b

When used as a non-specific tranquilizer, the medication should be used in conjunction with one or more of the following:

Behaviour therapy

Family or caretaker therapy

Residential treatment

Remedial education

Other psychotherapies

c. Rare.