Doctor Catherine Orrell has specialised in the use of medication. She has a particular interest in how and why people do or do not take their tablets every day (medication adherence). She can help you simplify the combination of medications you are taking; to reduce side effects and minimise drug interactions in order to make swallowing medications every day a bit easier.


For the last 20 years Catherine has cared for people living with HIV. She has extensive experience in the use of HIV medications, antiretroviral therapy (ART), which are used both to treat and to prevent HIV infection. She enjoys working together with her patients to make a treatment plan most suitable for their needs and for the optimal management of their illness.

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HIV Prevention

There are a number of options for protecting yourself from being infected with HIV. In South Africa today, the people most a risk of being infected are young women in their first few years of having sex (19-24 years old); and men who have sex with men. Anytime you have sex without using a condom you are at risk of being infected with HIV.


I can provide risk reduction counselling and advise you on the best methods currently available to prevent HIV, including daily Truvada®, and support you in tailoring HIV prevention options to suit your needs.

HIV Treatment

Living with HIV does not have to be difficult. With the correct treatment, most people with HIV live long and healthy lives. HIV treatment is getting safer and easier to take as the years go by. Today, treatment begins with a single daily tablet, that works safely and efficiently to suppress HIV.


My specialty is working with people who struggle to take their tablets every day; and with those whose HIV has learnt about the easier first-line options (HIV resistance) and who must take more complicated second and third line treatments for HIV.

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Simplify Treatment

Adherence to medication

Being adherent to a medication starts with collecting the prescribed medication at a pharmacy (many people do not!); then managing to take the daily dose as your doctor described and expected; and lastly, continuing to take the treatment for as long as is needed. This might be taking a capsule of antibiotic every 8 hours for 5 days; or it might be taking 1 or more daily tablets for life e.g. for high blood pressure or HIV.


As we are people, with busy lives, it is not unexpected that tablets can be forgotten or missed. In some illnesses the consequences of regular missed doses are serious.


I can help explore the best methods for you to remember to take your treatment, safely, every day.

Treatment simplification

If you have to take a number of medications for a number of different reasons, you might experience side effects (adverse effects) from some the medicines alone or because there are interactions between your medicines (drug interactions); or just be tired of taking so many tablets.


I can help you simplify your treatment by working with your provider to optimise your drug regimen while maintaining control of your illness. This would include a review of all your medicines to check how well you are taking them; how well they go together and perhaps taking some blood to check the levels of certain medications in your blood (therapeutic drug monitoring). Often by tweaking a dose or changing a medicine within a group or type the problem you are experiencing can be improved.