This Manual does not seek to give specific recommendations for treatments. With mental illnesses – as with other conditions, but maybe even more so – a drug that suits one person may not work for another or produce unacceptable side effects, and psychopharmacology is often a matter of judgement, experience and working with the patient to achieve better stability. However certain medications have interactions with HIV drugs that not all GPs, for instance, will know by heart so it is important that if you are prescribed drugs by someone who is not your HIV clinician you make them aware of what anti-retrovirals and/or other medication you are on. This includes complementary practitioners – see below.

This list only covers drugs used to treat diagnosed mental illnesses; there are a range of other drugs used for organic neurological disorders like epilepsy.

Antidepressants

There are three main types of anti-depressant drugs:

• Tricyclic anti-depressants (TCAs) were developed in the 1950s, including amitriptyline, nortriptyline (Allegron) and desipramine. Side-effects include confusion, drowsiness, dry mouth, weight gain, blurred vision and sexual problems.
• Monoamine oxidase inhibitors (MAOIs) include phenelzine (Nardil), isocarboxazid and tranylcypromine. These drugs can cause side-effects, including tremors, insomnia, weight gain and liver toxicity, and may interact with some foods to cause a sudden, life-threatening increase in blood pressure. As a consequence, these drugs are rarely prescribed.
• Selective serotonin re-uptake inhibitors (SSRIs) are the most recent type of anti-depressant to be developed. The group includes fluoxetine (Prozac), citalopram (Cipramil), escitalopram (Cipralex), fluvoxamine (Faverin), paroxetine (Seroxat) and sertraline (Lustral). Due to their better side-effect profile, these drugs are more frequently prescribed than the other drug classes. Nevertheless, a significant proportion of people experience early side-effects such as diarrhoea, insomnia, giddiness and nausea. These usually resolve after one to two months of treatment. Fluoxetine tends to be prescribed more frequently than other SSRIs because of a larger body of experience in its use and fewer concerns about potential for withdrawal symptoms. Citalopram is also often used because it has the least interaction with antiretrovirals. SSRIs also have fewer interactions with other drugs and do not usually cause weight gain, although they can affect sexual function. Impotence or delayed ejaculation are side-effects which may affect 10-20% of people taking fluoxetine, for example.
• Other drugs sometimes used as antidepressants include mirtazepine (which often causes weight gain) and venlafaxine (Efexor).

Antidepressants of all classes have the potential for interaction with the protease inhibitors, especially ritonavir.

Drugs for anxiety

• Beta-blockers do not reduce anxiety as such but inhibit the effect of adrenaline on the sympathetic nervous system. They reduce the physical symptoms of anxiety such as racing heart, sweating, hyperventilation and so on, which may in themselves give rise to more anxiety. They also have many other uses such as correcting heart arrhythmias. Commonly-used ones include propanolol, atenolol, carvetidol and metoprolol. The potential exists for overdose if combined with protease inhibitors; side effects include irregular heartbeat and kidney problems.
• Anxiolytics directly reduce anxiety and are perhaps better known as tranquillisers. The only class generally used these days are the benzodiazepines, which include diazepam, alprazolam and oxazepam. Lorazepam has a more strongly sedating effect and chlodiazepoxide is often used for alcohol withdrawal in people with dependency.
• Temazepam, loprazolam, nitrazepam and flurazepam are used solely as sleeping pills as their sedative effect is more pronounced; the latter two drugs can produce a ‘hangover effect’ of drowsiness the following day, as can zopiclone, a non-benzodiazepine. Doctors are reluctant to prescribe the benzodiazepines, especially for anxiety, as they all have the potential to cause addiction even after quite short-term use; however they are still sometimes prescribed on a short-term basis for acute anxiety and insomnia. When patients are taking protease inhibitors, especially ritonavir, indinavir and especially ritonavir, extreme caution should be taken when prescribing diazepam, flurazepam and alprazolam, and European agencies recommend that diazepam and flurazepam should not be co-administered with ritonavir, though US guidelines, which are more recent, just urge caution.
• The benzodiazepines midazolam and triazolam must not be co-administered with protease inhibitors.
• The old-fashioned barbiturates are now no longer prescribed as the window between an effective dose and a toxic dose is very narrow and becomes more so as the body develops tolerance to them.

Anti-psychotics

• These drugs are often mislabelled ‘major tranquilisers’. While they do have sedative effects they do a lot more than this, calming down disordered thought processes and controlling other psychotic symptoms such as hallucinations. You don’t have to have a diagnosed psychosis to be given an anti-psychotic; anyone has the capacity for entering a state of temporary psychosis, for instance during an extreme reaction to a recreational drug or during fever-induced delirium. No doctor would prescribe an anti-psychotic for sedation alone; these are strong drugs with a wide range of side effects, the chief one of which is a Parkinson’s disease-like syndrome in long-term users. Nonetheless they enable some people with illnesses like schizophrenia to lead relatively normal lives. The ones most commonly used are chlorpromazine, haloperidol, olanzapine and risperidone. This is not a complete list; these are just the most common ‘first line’ drugs. The antipsychotic pimozide must not be co-administered with protease inhibitors or efavirenz; data is incomplete on some of the others.

Bipolar illness and mania

• Salts of the metallic element lithium have a special place in psychopharmacology as they were until recently the only drug that seemed to work to prevent the mood swings of bipolar affective disorder (‘manic depression’) and particularly manic episodes. Lithium has a narrow therapeutic window between efficacy and toxicity; it needs to be taken strictly every 12 hours and drug levels in the patient’s body need regular monitoring.
• The anti-convulsant (anti-epilepsy) drugs carbamazepine and valproic acid however are also now used in bipolar illness, especially when lithium has proved ineffective. Carbamazepine can cause liver toxicity.

Complementary remedies

• The herbal remedy St John’s wort (Hypericum) has proven anti-depressant properties, and one recent study found it produced a 25% greater reduction in depression symptoms than the antidepressant paroxetine (Seroxat)(Szegedi). However, two different studies have found that St John's wort reduces the concentration of the protease inhibitor (PI) indinavir (Piscitelli) and the non-nucleoside (NNRTI) nevirapine (de Maat) in the body, in the case of indinavir by 80%.  It also reduces oral contraceptive pill levels, potentially resulting in unwanted pregnancy, and interacts with anticonvulsants, potentially resulting in someone having a seizure or epileptic fit.
• A number of herbal remedies are used to calm anxiety. One of the few for which some evidence of efficacy exists is valerian; one study (Andreatini) found it had similar efficacy to diazepam in calming the psychological aspects of generalised anxiety disorder. However others have found no difference from placebo. No studies have as yet been conducted on the interactions of valerian with anti-HIV medications.

Many other complementary therapies may be useful in calming anxiety and relieving depression; for more details see the NAM Directory of Complementary Therapies.

References

Andreatini R Effect of valepotriates (valerian extract) in generalized anxiety disorder: a randomized placebo-controlled pilot study. Phytother Res. 16(7): 650-654, 2002.

de Maat MM et al. Drug interaction between St John's wort and nevirapine. AIDS 15(3): 420-421, 2001.

Piscitelli SC et al. Indinavir concentrations and St John's wort. Lancet 355(9203): 547-548, 2000.

Szegedi A et al. Acute treatment of moderate to severe depression with hypericum extract WS 5570 (St John's wort): randomised controlled double blind non-inferiority trial versus paroxetine. BMJ 330: 503, 2005.