The Straits Times
13 July 2008
The 'morning after' HIV drug cocktail
It may keep virus at bay if taken in time but does not always work
By Braema Mathi
The 30-year-old businessman was on a working trip in Bangkok. He visited a male prostitute on his last night in the city. Against his better judgment, they had unprotected sex. But the next morning, he was seized by panic with the sudden realisation he might have exposed himself to HIV - the retrovirus that can lead to Aids.
Upon landing in Singapore that afternoon, he headed straight for the Department of Sexually Transmitted Infections Control (DSC). Not only did he get an Aids test, but he also asked to be prescribed post-exposure prophylaxis (PEP).
He had read that the cocktail of antiretroviral drugs with Zidovudine works like a 'morning after' HIV prevention course and may keep the virus at bay. He paid a hefty $1,230 for a 28-day course of PEP, put up with the side effects, including severe diarrhoea, and saw the doctor weekly. He breathed a sigh of relief when another HIV test three months later pronounced him clean.
PEP was first administered in 1998 to health-care staff working with HIV patients in San Francisco, who risked infection from needlestick injuries. It was also used for health-care workers in Singapore around the same time.
Dr Tan Hiok Hee, head of the DSC clinic and senior consultant at the National Skin Centre, told The Sunday Times that the centre made PEP available to the public in 2004. It can also be prescribed by doctors in private practice here.
Since then, Dr Tan has treated 22 people with the drug cocktail. Dr Lin Li from the Communicable Diseases Centre has treated three. The patients - educated, mostly professionals and all males save one - sought treatment after unsafe sex. All tested negative after completing their treatments although it is not known if their sex partners were HIV positive in the first place.
Doctors interviewed by The Sunday Times took great pains to emphasise that PEP does not always work and cannot replace safe-sex practices. 'Studies have shown that PEP is not 100 per cent foolproof against HIV. Its efficacy is around 81 per cent,' said Dr Tan. There have also been reported studies, he added, of at least 20 health-care workers overseas succumbing to HIV despite being treated with PEP.
Dr Lin explained that upon exposure, it takes less than two hours for the HIV virus to start coursing through the body of a person or to lodge itself in the cells. She said the cocktail is best taken as early as possible - not beyond the window period of 72 hours after exposure to the virus.
Only then is there a chance that the drug cocktail can 'wipe out the HIV from the blood, not allowing it to infect another cell even if the first one in which it is lodged dies''. 'It is a race against time - PEP versus the virus - to see which gets into the blood stream first,' added Dr Lin.
'Once the HIV gets established in the brain, the lymph nodes or the testes, it has found its sanctuary in the human body and drugs will find it harder to reach the virus.'' Dr Tan noted that PEP comes with a price - side effects, costs and clinical management. Patients often experience nausea, diarrhoea, anorexia, rash, hair loss, headaches, insomnia and pigmentation on nails. They also need consultations and tests at intervals of between three and six months.
This is important as PEP can, in the course of 28 days, suppress the formation of antibodies to the HIV, reflecting a negative result. A positive HIV result is achieved through the presence of antibodies in the blood. Also, an all-clear does not mean that the person is free of HIV. The virus can remain in the body without converting cells into infected ones.
Dr Tan said it is important to complete the PEP regimen and not forgo it after the initial HIV tests come back negative. 'Taking PEP will also involve loss of days at work to cope with the side effects and consultations.
Then there is the constant anxiety. It is better any day to wear a condom, be safe, than to go through this.' Still PEP, combined with other drugs, has been useful in preventing mother-to-child transmission of the HIV virus, as well as protecting victims of sexual assaults.
Rape victims often end up with lacerations on the anal and vaginal walls, leaving them more vulnerable to HIV and other sexually transmitted diseases. In Singapore, emergency department doctors will prescribe PEP to rape victims if necessary.
Doctors and Aids workers said that the drug cocktail is not a substitute for ABC, the cardinal rules of safe sex: abstain, be faithful to partners, and use condoms. Counselling and education are also important.
Dr Lin said: 'As human beings, we always like to think that it will not happen to us. That is why people still take the risk.' Indeed, the number of reported HIV/Aids cases in Singapore has been rising - from 0.8 cases per million in 1985 to 98.9 infections per million in 2006. The main mode of transmission is sexual contact.
There were 422 new HIV infections last year, the highest number in a single year since records started in 1985. As of the end of last year, 3,482 persons in Singapore had contracted HIV/Aids, of whom 1,144 died. Said Dr Tan: 'PEP is not a panacea given by doctors. The drug plays a small role.
What is more important is for people to choose their partners carefully, be faithful and/or practise safe sex.'
13 July 2008
The 'morning after' HIV drug cocktail
It may keep virus at bay if taken in time but does not always work
By Braema Mathi
The 30-year-old businessman was on a working trip in Bangkok. He visited a male prostitute on his last night in the city. Against his better judgment, they had unprotected sex. But the next morning, he was seized by panic with the sudden realisation he might have exposed himself to HIV - the retrovirus that can lead to Aids.
Upon landing in Singapore that afternoon, he headed straight for the Department of Sexually Transmitted Infections Control (DSC). Not only did he get an Aids test, but he also asked to be prescribed post-exposure prophylaxis (PEP).
He had read that the cocktail of antiretroviral drugs with Zidovudine works like a 'morning after' HIV prevention course and may keep the virus at bay. He paid a hefty $1,230 for a 28-day course of PEP, put up with the side effects, including severe diarrhoea, and saw the doctor weekly. He breathed a sigh of relief when another HIV test three months later pronounced him clean.
PEP was first administered in 1998 to health-care staff working with HIV patients in San Francisco, who risked infection from needlestick injuries. It was also used for health-care workers in Singapore around the same time.
Dr Tan Hiok Hee, head of the DSC clinic and senior consultant at the National Skin Centre, told The Sunday Times that the centre made PEP available to the public in 2004. It can also be prescribed by doctors in private practice here.
Since then, Dr Tan has treated 22 people with the drug cocktail. Dr Lin Li from the Communicable Diseases Centre has treated three. The patients - educated, mostly professionals and all males save one - sought treatment after unsafe sex. All tested negative after completing their treatments although it is not known if their sex partners were HIV positive in the first place.
Doctors interviewed by The Sunday Times took great pains to emphasise that PEP does not always work and cannot replace safe-sex practices. 'Studies have shown that PEP is not 100 per cent foolproof against HIV. Its efficacy is around 81 per cent,' said Dr Tan. There have also been reported studies, he added, of at least 20 health-care workers overseas succumbing to HIV despite being treated with PEP.
Dr Lin explained that upon exposure, it takes less than two hours for the HIV virus to start coursing through the body of a person or to lodge itself in the cells. She said the cocktail is best taken as early as possible - not beyond the window period of 72 hours after exposure to the virus.
Only then is there a chance that the drug cocktail can 'wipe out the HIV from the blood, not allowing it to infect another cell even if the first one in which it is lodged dies''. 'It is a race against time - PEP versus the virus - to see which gets into the blood stream first,' added Dr Lin.
'Once the HIV gets established in the brain, the lymph nodes or the testes, it has found its sanctuary in the human body and drugs will find it harder to reach the virus.'' Dr Tan noted that PEP comes with a price - side effects, costs and clinical management. Patients often experience nausea, diarrhoea, anorexia, rash, hair loss, headaches, insomnia and pigmentation on nails. They also need consultations and tests at intervals of between three and six months.
This is important as PEP can, in the course of 28 days, suppress the formation of antibodies to the HIV, reflecting a negative result. A positive HIV result is achieved through the presence of antibodies in the blood. Also, an all-clear does not mean that the person is free of HIV. The virus can remain in the body without converting cells into infected ones.
Dr Tan said it is important to complete the PEP regimen and not forgo it after the initial HIV tests come back negative. 'Taking PEP will also involve loss of days at work to cope with the side effects and consultations.
Then there is the constant anxiety. It is better any day to wear a condom, be safe, than to go through this.' Still PEP, combined with other drugs, has been useful in preventing mother-to-child transmission of the HIV virus, as well as protecting victims of sexual assaults.
Rape victims often end up with lacerations on the anal and vaginal walls, leaving them more vulnerable to HIV and other sexually transmitted diseases. In Singapore, emergency department doctors will prescribe PEP to rape victims if necessary.
Doctors and Aids workers said that the drug cocktail is not a substitute for ABC, the cardinal rules of safe sex: abstain, be faithful to partners, and use condoms. Counselling and education are also important.
Dr Lin said: 'As human beings, we always like to think that it will not happen to us. That is why people still take the risk.' Indeed, the number of reported HIV/Aids cases in Singapore has been rising - from 0.8 cases per million in 1985 to 98.9 infections per million in 2006. The main mode of transmission is sexual contact.
There were 422 new HIV infections last year, the highest number in a single year since records started in 1985. As of the end of last year, 3,482 persons in Singapore had contracted HIV/Aids, of whom 1,144 died. Said Dr Tan: 'PEP is not a panacea given by doctors. The drug plays a small role.
What is more important is for people to choose their partners carefully, be faithful and/or practise safe sex.'
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