While sexual dysfunction can be a problem for anyone, people living with HIV may be particularly affected. Loss of sexual drive or desire (libido) or the inability to obtain and sustain an erection can have a significant impact on quality of life and feelings of self-worth, and may even contribute to emotional problems including anxiety and depression.

Sexual problems are common during times of stress, such as being diagnosed HIV-positive or experiencing work or relationship difficulties. Excessive intake of alcohol or recreational drugs can also diminish both the desire and ability to have sex.

Some anti-HIV drugs and many of the drugs commonly used to treat depression, e.g. citalopram or fluoxetine (Prozac) or can also affect sexual function. Additionally, megestrol acetate (Megace), an appetite stimulant, has been shown to cause loss of libido.

Sexual dysfunction among men can often be a result of decreased testosterone levels (hypogonadism), which can also lead to fatigue. Lower than normal testosterone levels have been found in people with advanced HIV infection, and can be caused both by the direct effects of HIV or chronic ill health itself. Many males receive testosterone treatment to alleviate these problems. Men who use testosterone replacement therapy usually gain muscle mass, experience an emotional ‘lift’, and an increase in their libido.

HIV can also cause nerve damage that can result in erectile problems.

Furthermore, erectile problems can be a side-effect of some anti-HIV drugs.  For example ddI (Videx) and d4T (stavudine, Zerit) can cause numbness in the genital area. Some, but not all research has linked protease inhibitors with erectile problems. 

The risk of developing erectile problems increases with age and these can sometimes be an indication of more serious problems such as heart disease.

So it makes good sense to mention erectile or other sexual problems to your doctor so the cause can be investigated and the most appropriate treatment provided.

Viagra (sidenafil), Cialis (tadalafil) and vardenafil (Levitra) are tablets used to treat erectile dysfunction (or impotence) that work by increasing blood flow to the penis, making it more sensitive to touch. 

These drugs should be taken with care by people using protease inhibitors, NNRTIs, ketoconazole, itraconazole or erythromycin. The standard doses of Viagra should be reduced to 25mg, Cialis to 10mg and Levitra to 2.5mg. However, for people taking full-dose ritonavir, it is recommended that Viagra should not be used at all given the potential health risks and that the dose of Levitra should be reduced to no more than 2.5mg in 72 hours. Similarly, the recreational drug poppers should not be used with Viagra, Cialis or Levitra as this could result in a potentially dangerous drop in blood pressure.

Older treatments for impotence include the injection of alprostadil, a hormone produced by the prostate gland that alters the flow of blood in the penis. This can be done using Caverject, a tiny needle used to inject the penis with the hormone. This works very quickly, and the effects can last for hours, though some men may find the process unappealing. The long-term effects are unknown and there is a limit of three injections a week, otherwise you run the risk of priapism, or persistent painful erection of the penis. Alternatively, alprostadil comes as a pellet which you insert into the urethra using an applicator. This is known as Muse.

A range of different implants are also available, but these will need replacing as time passes. A semi-solid silicone implant can make the penis firmer, though not hard. Alternatively, a pocket can be created within the penis, into which a silicone rod is inserted to form an erection. Vacuum pumps, including the Rapport pump, are also available on the NHS.

It is not uncommon for HIV-positive women to experience early menopause as a result of abnormal production of the female hormones progesterone and oestrogen. Sexual dysfunction among women can also be caused by physical symptoms such as vaginal dryness or thrush, pain or severe pre-menstrual syndrome (PMS). Women can be offered hormone replacement therapy, though this should be carefully monitored for signs of masculinisation. None of the sexual dysfunction drugs have been fully studied in women.

If you have concerns about any aspect of sexual dysfunction, consider talking it through with your doctor at your next hospital visit. He or she may be able to refer you to a specialist within the hospital, such as a psychologist or psychotherapist. If the underlying causes of the problem are emotional, then you may find that medications provide only partial benefit. A short course of sessions with a psychologist or counsellor may provide additional help.