Drug-induced Photosensitivity

Drug-induced photosensitivity is quite common. In fact, researchers estimate that about 3,000 drugs can cause this effect. It can appear as a phototoxic reaction or as a photoallergic reaction.

Both phototoxic and photoallergic reactions are photosensitivity reactions, but not all photosensitivity reactions are phototoxic or photoallergic. However, they are all abnormal reactions that occur on the skin after sun exposure and after taking certain drugs.

Especially during the summer it is important to be careful with this kind of problem. Therefore, both doctors and patients should be informed about which drugs can cause this problem and what reactions they can cause.

What is drug-induced photosensitivity?

As we mentioned, this condition is a skin reaction that occurs when the sun’s rays hit the skin and react with certain chemical compounds in the ingested drugs that can induce photosensitivity.

These compounds, which react with the light spectrum between visible light and ultraviolet radiation, can be both the active ingredient and one of the excipients that make up the formula. It is worth noting that 8% of all side effects are and photosensitivity reaction.

The patient’s skin pigmentation is one of the risk factors. The more pigmented the skin is, the greater the chance of drug-induced photosensitivity. In addition to pigmentation, other groups of people are also prone to this problem. This applies, among other things, to:

• Patients being treated with NSAIDs for chronic pain.
• Cancer patients being treated with chemotherapy.
• People with psychiatric illness who are treated with phenothiazines.
• Patients with high blood pressure taking thiazide diuretics as a treatment.
• The elderly and patients with a weak immune system.

What is a phototoxic reaction?

As we mentioned earlier, a phototoxic reaction is a form of drug-induced photosensitivity. Unlike a photoallergic reaction, as we will see later, the immune system plays no role in a phototoxic reaction.

Phototoxic reactions represent 95% of all drug-induced photosensitivity symptoms. They can develop a few minutes or hours after taking the drug and the main symptoms include:

• Erythema and Edema
• Itchy blisters
• Symptoms similar to severe sunburn

These reactions are more common with oral medications and are caused by creating free radicals that interact with oxygen, resulting in highly reactive and cell-damaging chemicals.

What is a photoallergic reaction?

This is another type of drug-induced photosensitivity. This type of reaction, as mentioned above, involves the immune system. To cause a photoallergic reaction, UV rays must cause a chemical transformation of the ingested drug.

The drug is converted into another chemical called hapten, which interacts with skin proteins and eventually triggers an immune system response.

One of the most common symptoms is eczematous inflammation if you have taken the medicine orally, or a rash if you have applied it to the skin.

Which drugs can cause induced photosensitivity?

Many drugs can cause this type of reaction. That is why you should always check the package leaflet of the medicines to know whether they can cause these complaints or not.

However, we have put together a short list of some of these drugs for you. Remember, there are of course many more, so you should always consult your doctor or pharmacist.

• Antimicrobial agents such as tetracyclines, cephalosporins, or tuberculosis medications.
• Cardiovascular drugs: thiazides, ACE inhibitors or statins.
• Hypoglycemic drugs, which are drugs that lower glucose levels.
• NSAIDs or non-steroidal anti-inflammatory drugs.
• retinoids.
• Psychoactive drugs.

• Chemotherapeutic agents.
• Antihistamines.

Learning about medicine is key

It is essential to be informed about the side effects that drugs can cause. To do this, you can read the package insert as well as the guidelines from your pharmacy. In addition, consult your doctor when the medication is prescribed.

Drug-induced photosensitivity is indeed common, and it is very important to know what the triggers are to avoid symptoms when taking this medication.