Published: June 2011
Publications
Seeing drug induced glaucoma?
Prescriber Update 32(2): 15-16
June 2011
Prescribers are reminded that glaucoma can be caused by many medicines (see table opposite). Glaucoma is characterised by optic nerve damage and visual field loss resulting primarily from increased intraocular pressure.1 It can generally be classified as angle-closure or open-angle glaucoma.
Angle-closure glaucoma is a medical emergency and confers a risk of blindness within days of onset if left untreated.1 The most common symptoms of angle-closure glaucoma include sudden, severe eye pain, eye redness and decreased or cloudy vision. Other symptoms include nausea and vomiting, rainbow-like halos around lights and feeling of swelling in the eyes.1 Symptoms may initially occur intermittently.
Most cases of drug-induced angle-closure glaucoma occur in susceptible patients such as those with a pre-existing abnormally narrow angle or patients with other risk factors for glaucoma (see table opposite).
Proposed mechanisms for drug-induced glaucoma include sudden dilation of the pupil, forward movement of the iris/lens diaphragm or swelling of the ciliary body, lens or vitreous body. In susceptible patients, these events may result in further narrowing or blockage of the angle; thereby triggering angle-closure glaucoma.4
Open-angle glaucoma is the most common type of glaucoma. It generally presents with a gradual and painless loss of vision.4
| Medicines associated with drug-induced glaucoma1,2-4 | Risk factors for glaucoma1,4 |
|---|---|
|
Glucocorticoids (inhaled and topical) Adrenergic agonists (ephedrine and broncodilators) Serotinin re-uptake inhibitors Medicines with anticholinergic effects (such as TCAs and tiotropium) Sulpha-based medicines (such as topiramate and cotrimoxazole) |
Narrow angle or shallow anterior chamber Previous angle closure Family history Severe hypermetropia Advanced age Female gender Ethnicity (higher prevalence in Asian and Hispanic) Use of substances that cause pupil dilation |
As at 31 December 2010, CARM had received 20 reports of suspected drug-induced
glaucoma or worsening glaucoma. These reports were associated with a variety
of medicines including glucocorticoids, phenylephrine, venlafaxine, ipratropium,
and ipratropium combined with salbutamol. Most cases involved patients with
additional risk factors for glaucoma such as advanced age or female gender.
All patients with suspected angle-closure glaucoma should be referred to an ophthalmologist immediately, as rapid diagnosis and treatment to reduce intraocular pressure is vital to saving a patient's vision. Patients with existing open angle glaucoma should already be under ongoing ophthalmological review and should advise their ophthalmologist about any new medication being taken.
Healthcare professionals should be mindful of the potential for glaucoma to be caused by medicines. If symptoms of intermittent angle closure are reported, any suspect medicines should be tapered or discontinued as soon as possible.1 Specialist advice should be sought if this is not possible.
Healthcare professionals are encouraged to report all suspected cases of drug-induced glaucoma from any medicine, to the Centre for Adverse Reactions Monitoring (CARM).
References
- Richa S. and Yazbek J. (2010). Ocular adverse effects of common psychotropic agents. CNS Drugs. 24(6): 501-526.
- Subak-Sharpe I., et al. (2010). Pharmacological and environmental factors in primary angle-closure glaucoma. British Medical Bulletin. 93: 125-143.
- Lachkar Y. and Bouassida W. (2007). Drug-induced acute angle closure glaucoma. Current Opinion in Ophthalmology. 18(2): 129-133.
- Li J., Tripathi R. and Tripathi B. (2008). Drug-induced ocular disorders. Drug Safety. 31(2): 127-141.
