Chloramphenicol

What is chloramphenicol?

Chloramphenicol is an antibiotic used to treat a broad spectrum of bacterial infections, most commonly used for eye infections like conjunctivitis and sometimes ear infections[1]. The eye drops, and eye ointment forms of chloramphenicol are also known by the brand name Optrex.

What is chloramphenicol used for?

Chloramphenicol is used to treat a range of infections. These can include eye infections such as bacterial conjunctivitis, ear infections, and some more serious infections such as meningitis or typhoid fever (mostly under specialist supervision in a hospital)[1].  

How does chloramphenicol work?

Chloramphenicol works by blocking bacteria from producing essential proteins for growing and thriving. Without these proteins, bacteria cannot continue to multiply within the body. Over time, this stops the infection from spreading and allows your immune system to remove the bacteria and make a recovery[1]. 

Who can take chloramphenicol?

Chloramphenicol is generally suitable for most adults and children. If used for bacterial conjunctivitis chloramphenicol eye drops and ointment can also be purchased over the counter for adults and children aged 2 and over, , while children under 2 will still need a prescription[1]. 

However, chloramphenicol may not be suitable in the following[2]: 

• If you ever had an allergic reaction to chloramphenicol 

• If you have a history of blood disorders or bone marrow problems such as aplastic anaemia 

Chloramphenicol eye drops and eye ointment may not be suitable[2]: 

• If you have changes in your vision or severe pain in the eye 

• If you have unusual pupils (size, dilation, no reaction to light) 

• If you have an eye injury or had recent surgery on the eye  

• If you have glaucoma (increased pressure inside the eye) or dry eyes  

• If you recently had conjunctivitis  

Please tell your doctor or pharmacist about any conditions you may have before you start treatment and always follow the instructions in the Patient Information Leaflet[2]. 

How do you take chloramphenicol?

How you take chloramphenicol depends on the form you are using[1]: 

• With eye drops, you can tilt your head back, pull down the lower eyelid, and apply one drop into the eye. After application keep the eye closed and press your fingertip against the inside corner of the closed eye for 1 minute. 

• If using eye ointment, tilt your head back and pull down the lower eyelid then squeeze a thin strip of ointment (about 1cm) inside the lower eyelid. Close your eye then blink a few times to help spread the ointment. When using ear drops, lie on your side and put the drops into the affected ear canal, giving them a little time to sink in. 

• Take capsules by swallowing with water, with or without food (capsules are rarely prescribed as they are primarily used for the treatment of typhoid fever and other dangerous infections where other antibiotics are not effective). 

You should always wash your hands before and after applying drops or ointment. And with all types of treatment, follow the instructions on the label or as prescribed by your doctor.

What is the typical dosage of chloramphenicol?

The dosage and application of your chloramphenicol treatment will depend on your condition and type of medicine prescribed. Treatment usually lasts from 3 to 5 days, unless advised otherwise by your doctor.  

For the treatment of bacteria conjunctivitis, eye ointment is recommended to be used 3-4 times a day, whereas eye drops may be used every 2 hours (waking hours only) for the first 48 hours of treatment, then reduced to every 4 hours for a further 3 days.  

Always follow the dosage on the label or as prescribed by your doctor or pharmacist[1]. 

Can you stop taking chloramphenicol suddenly?

You should not stop the medication until you have completed the full course of chloramphenicol, even if you feel better, unless advised by a medical professional. This is because stopping too early can lead to the infection coming back or bacteria becoming resistant to antibiotics[1]. 

What should you do if you take too much chloramphenicol?

Taking a few extra drops or applying too much ointment shouldn’t have any impact. However, taking far too much chloramphenicol – particularly if you are taking the capsule form – can bring serious side effects. You might feel generally unwell, see unusual bruising or bleeding, or have signs of infection such as fever or sore throat. Contact your doctor or go to A&E if you or someone else may have overdosed[1]. 

What should you do if you forget a dose of chloramphenicol?

If you forget to take chloramphenicol drops or ointment, take a dose as soon as you remember. If it is nearly time for your next dose, skip the missed one and just carry on with your schedule[1]. 

Similarly, if you are taking capsules, you can take the missed dose unless it’s almost time for your next dose. If it is, skip the missed one and carry on. Do not take a double dose to make up for a missed one. 

What medicines should you avoid while taking chloramphenicol?

You should inform your doctor or pharmacist if you are taking any of the following medications[1]: 

• Warfarin 

• Methotrexate or medicines used to treat cancer  

• Other immune system suppressants such as azathioprine 

If you have been prescribed chloramphenicol in the oral capsule form you should also inform your doctor if you are using any medicines for diabetes, antipsychotics, certain antibiotics and antivirals, medicines used for an overactive thyroid, and the combined contraceptive pill. If you already take any of these, you may require an alternative to chloramphenicol. 

Always inform your doctor or pharmacist about all medications and supplements you take before you start a new medicine, and follow the instructions in the Patient Information Leaflet[2].

What are the side effects of chloramphenicol?

Common and mild side effects when using chloramphenicol drops or ointment include: 

• Mild irritation, like stinging or burning in the eyes or ears 

• Temporary blurred vision after using eye drops or ointment[1]. 

The rarer but more serious side effects  include[1]: 

• Bruising  

• Getting infections more easily 

• Feeling tired or weak 

You should contact your GP or call NHS 111 if you experience any of these symptoms. In rare cases, the medicine may cause a serious allergic reaction (anaphylaxis). You should call 999 or visit A&E immediately if you believe this is happening[1]. 

If you experience any side effects, including those not listed, you are encouraged to report them via the Yellow Card Scheme or contact your doctor, pharmacist, or nurse. This information is intended as a summary for general awareness and does not replace professional medical advice. 

The information provided in the side effects section is not a comprehensive list of all possible side effects associated with this medication. For a complete list of side effects, please refer to the Patient Information Leaflet (PIL) provided with your medication or consult your healthcare professional[2]. 

Frequently asked questions about chloramphenicol

Can I wear contact lenses while using chloramphenicol? 

No, you should remove contact lenses before using chloramphenicol eye drops or ointment. Then wait at least 24 hours after finishing treatment before wearing them again. This will give your treatment the time and conditions to work properly[1]. 

Can I drive after using chloramphenicol? 

Your vision may be temporarily blurred after using the eye drops or ointment, so it’s best to use them well before you expect to drive. You should always wait until your vision is clear before driving or operating machinery[1]. 

Is chloramphenicol safe in pregnancy or breastfeeding? 

It is usually safe to use chloramphenicol in drop or ointment form when you are pregnant or breastfeeding. However, it is not currently known how much chloramphenicol passes into breast milk and you should always consult your doctor before using it just to be safe[1]. 

For the official NHS guide to chloramphenicol, visit their website.