Carbamazepine is sometimes used for manic depression (bipolar disorder) when lithium has not been effective.
This is a low-dose preparation of an antipsychotic, which is used in higher doses to treat severe mental distress such as schizophrenia. It should be used for short-term treatment only. As this drug tends to take effect quickly, if there is no improvement within one week, manufacturers advise that treatment be stopped.
Adult dose: 1mg initially in the morning, increasing after one week to 2mg if necessary. Maximum dose 3mg daily in divided doses, not later than 4pm.
Older people: 0.5mg initially, increasing to 1mg if necessary. Maximum: 2mg daily in divided doses, not later than 4pm. Side effects: restlessness, insomnia, and overactive and excitable behaviour. Rarely: dizziness, tremor, visual disturbances, headache, raised blood prolactin levels (a hormone involved in producing breast milk), movement disorders. If movement disorders occur, the drug should be stopped. Drug interactions: unwanted effects may be increased if given with other antidepressants. Taken with sleeping pills or anti-anxiety drugs, sedation will increase. Avoid alcohol as this also provokes drowsiness. Caution: skilled tasks such as driving can be affected. Should be avoided in excitable, overactive or manic people and used with caution in people with Parkinson’s disease, liver, kidney or heart disease or dementia. Withdrawal: should be stopped gradually.
Lithium (Camcolit, Liskonum, Priadel)
Mainly used for bipolar disorder, but may also be given as a preventive therapy where there are repeated episodes of severe depression. (See Making sense of lithium for more information.)
Tryptophan was re-introduced for ‘exceptional cases’ of treatment-resistant depression in 1994. It can only be prescribed by hospital specialists for people ‘who have had severe and disabling depression continuously for more than two years’. Both patient and prescribing doctor must be registered with the manufacturer.
Tryptophan is an amino acid present in the normal diet in small quantities. Used as an antidepressant since the 1970s, the then Committee on Safety of Medicines then withdrew it from general use in 1990 because it was associated with a serious illness eosinophilia-myalgia syndrome (EMS). This is a blood disorder bringing severe muscle pain, joint pain, fever, swelling and skin rash, which may involve the lungs and central nervous system. The company warns that EMS is ‘a multi-system disorder, which is usually reversible, but rarely fatal’. It states that various investigations have not as yet precisely identified the cause, which may have been associated with a contaminated batch of the drug. It recommends blood monitoring (for eosinophil, a particular white blood cell) and monitoring for any muscular symptoms. Safety questionnaires are issued to the prescriber every three months to begin with, and thereafter six-monthly. The Committee on Safety of Medicines reviews the information.
Adult dose: 1g three times daily to a maximum of 6g daily.
Older people: a lower dose may be appropriate, especially for those with kidney or liver disease.
Side effects: drowsiness, nausea, headache, light-headedness, eosinophilia-myalgia syndrome (see above).
Drug interactions: the BNF warns that prescribing Optimax with other antidepressants may be hazardous. They specify MAOIs and SSRIs; yet also indicate it should only be used as an adjunct to other antidepressant medications.
Caution: drug manufacturers point out that it is only available under the limited circumstances previously mentioned, and from hospital specialists. It should not be given to people who have had EMS following tryptophan use. Manufacturers advise against using it in pregnancy or while breastfeeding.