Bimatoprost

What is bimatoprost?

Bimatoprost is a prescription medicine used to lower pressure inside the eye, particularly in conditions like glaucoma or ocular hypertension. By reducing eye pressure, it helps prevent damage to the optic nerve and vision loss[1]. 

What is bimatoprost used to treat?

Bimatoprost is most commonly used to manage[1]: 

• Ocular hypertension (high pressure inside the eye) 

• Open-angle glaucoma 

It may also be used off-label to encourage eyelash growth in people with inadequate or sparse lashes. 

How does bimatoprost work?

Inside the eye, a fluid called aqueous humour maintains pressure and shape. In glaucoma or ocular hypertension, this fluid can build up, increasing eye pressure. Bimatoprost increases the outflow of this fluid, helping reduce that pressure. When applied to the lash line, it stimulates hair follicles, leading to longer, thicker, and darker eyelashes[1]. 

Who can take bimatoprost?

This medication is generally suitable for adults but you should speak to a doctor first if you[1]: 

• Have an eye infection or active eye inflammation 

• Have recently had eye surgery 

• Have dry eyes 

• Have cornea problems 

• Wear contact lenses 

• Have liver or kidney problems 

• Have low blood pressure or heart arrhythmia 

• Have asthma or COPD 

• Are allergic to silver 

• Have a history of eye pressure problems 

• Are pregnant or breastfeeding  

• Are a child under 18 

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

What is the typical dosage of bimatoprost?

Bimatoprost eye drops come in 2 strengths[1]: 

• 0.1mg/ml, where 1ml of liquid contains 0.1mg of bimatoprost 
  0.3mg/ml, where 1ml of liquid contains 0.3mg of bimatoprost 

The dose depends on the reason you’re using it[1]: 

• For glaucoma or ocular hypertension: One drop in the affected eye(s) once daily, typically in the evening. 

• For eyelash growth: One drop applied along the upper lash line only (not inside the eye) once a day at night. 

How do you use bimatoprost?

You should[1]: 

• Wash your hands before applying. 

• For eye drops, tilt your head back and gently pull down your lower eyelid. Apply one drop and close your eye. 

• For eyelash use, apply the solution to the base of the upper lashes using a sterile applicator. 

• Avoid touching the dropper to your eye or skin. 

• If you wear contact lenses, remove them before application and wait at least 15 minutes before putting them back in. 

Can you stop taking bimatoprost?

Do not stop using bimatoprost suddenly, especially if it's being used for glaucoma or high eye pressure. Stopping can cause pressure to rise again, which may damage your vision. For eyelash growth, stopping treatment will cause lashes to gradually return to their original appearance[1]. 

What do you do if you take too much bimatoprost?

If you use more than you should[1]: 

• Rinse your eye gently with water if it was an accidental extra drop. 

• If you swallow the medication or experience side effects, seek medical advice right away. 

• Overuse on the skin can lead to unwanted hair growth in areas where the solution touched. 

What do you do if you forget to take bimatoprost

If you forget to use bimatoprost[1]: 

• Apply it as soon as you remember 

• If it’s almost time for your next scheduled dose, skip the missed one 

• Do not apply two doses to make up for one you missed 

How do you store bimatoprost?

Store the bottle properly to keep it effective[1]: 

• Keep it in a cool, dry place, away from direct light 

• Keep the bottle tightly closed when not in use 

• Discard the bottle four weeks after opening (for eye drops) 

• Keep out of reach of children 

• Discard 28 days after opening 

What medicines can’t you take with bimatoprost?

Some medicines may interact with bimatoprost[1]: 

• Do not use other eye drops or glaucoma treatments unless advised by your doctor. 

• Tell your pharmacist or doctor if you use: 

• Steroid eye drops 

• Other medications for eye pressure 

• Herbal or over-the-counter products 

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 bimatoprost?

Most side effects are mild, but you should know what to expect. Common side effects include[1]: 

• Redness or itchiness in the eye 

• Eye irritation or a feeling of dryness 

• Darkening of the iris (which may be permanent) 

• Eyelid skin darkening 

• Longer, thicker, or darker eyelashes 

• Hair growth on the skin around the eye if the solution touches it 

Serious but rare side effects[1]: 

• Eye pain 

• Vision changes 

• Inflammation inside the eye 

You should contact your GP 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]. 

Symptoms of anaphylaxis include[1]:  

• Difficulty breathing  

• Tightness in throat and chest  

• Swelling of the tongue or throat  

• Feeling faint or dizzy  

• Blue/grey skin or lips  

• Loss of consciousness 

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 bimatoprost

How long does it take to work? 
For glaucoma, you may see results in a few weeks. For eyelash growth, it typically takes 4 to 16 weeks[1]. 

Can I use it with contact lenses? 
Yes but remove your lenses before using the drops and wait 15 minutes before reinserting them[1]. 

Can bimatoprost change eye colour? 
Yes, it may cause permanent darkening of the iris, especially in people with mixed-colour eyes[1]. 

Is it safe during pregnancy? 
No, it’s generally not recommended during pregnancy or breastfeeding. Consult your doctor or pharmacist[1]. 

Can I use it in both eyes? 
Only use it in both eyes if prescribed to do so[1]. 

What happens if I stop using it? 
For glaucoma, eye pressure may rise again. For eyelash use, the lashes will gradually return to their normal state[1]. 

Can children use it? 
It’s not recommended for anyone under 18 unless directed by a specialist[1]. 

Does it cause eyelash growth on other parts of the skin? 
Yes, if the solution spreads to other skin areas, it may cause hair growth there[1]. 

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