Question

A man being treated for chlamydial urethritis presents with severe erythema over his upper body after sun exposure. Which antibiotic is most likely responsible for this adverse effect? (A) azithromycin (B) clindamycin (C) doxycycline (D) erythromycin (E) mupirocin

Short answer

Doxycycline is most likely responsible for the photosensitivity reaction.

Step-by-step solution

Identify the Condition and Common Treatments

The patient is being treated for chlamydial urethritis. This condition is commonly treated with antibiotics such as azithromycin and doxycycline.

Recognize the Symptoms of the Adverse Effect

The patient experiences severe erythema over his upper body after sun exposure, which indicates a possible photosensitivity reaction.

Associate Photosensitivity with Antibiotics

Certain antibiotics are known to cause photosensitivity reactions. Doxycycline is well-known for causing increased sensitivity to sunlight, resulting in skin reactions like erythema.

Rule Out Other Antibiotics

Azithromycin, clindamycin, erythromycin, and mupirocin are less commonly associated with photosensitivity. Instead, doxycycline is a more likely candidate for causing photosensitivity.

Select the Most Likely Antibiotic

Considering the patient's symptoms and the common side effects of the listed antibiotics, doxycycline is the most likely antibiotic responsible for the severe erythema after sun exposure.

Key concepts

Photosensitivity Reaction

Photosensitivity reactions are skin responses that occur when the skin becomes extra sensitive to ultraviolet (UV) light. This happens when certain substances, like drugs or chemicals, react with sunlight. These reactions often show up as rashes or burns, even with minimal sun exposure. They can range from mild redness to severe blistering, similar to a sunburn. This makes it important for those prone to these reactions to take preventive measures, such as using sunscreen and wearing protective clothing when going out in the sun.
Even though anyone can get a sunburn, photosensitivity reactions can occur suddenly and can be more intense for someone not prone to sunburning. Understanding the potential triggers and how to protect against them can help individuals manage their health better and avoid uncomfortable situations.

Antibiotics Side Effects

Antibiotics are medicines used to prevent and treat bacterial infections. While they are effective in treating various illnesses, they can also come with side effects, some of which may impact the patient's health. Common side effects include upset stomach, diarrhea, and allergic reactions. However, specific antibiotics can have unique effects, such as photosensitivity.
It's important for patients to be aware of these effects so they're better prepared to manage them. Healthcare providers usually give advice on what to expect with certain antibiotics and how to adjust one’s routine. For example, some might recommend staying out of the sun or taking the medication with food to reduce stomach upset.
Understanding these side effects allows patients to use antibiotics safely, ensuring that they benefit from the treatment without additional discomfort.

Pharmacology Education

Pharmacology education plays a crucial role in helping healthcare professionals and students understand how drugs work in the body. It covers how medications are administered, how they interact with the body, and how they can produce intended effects or adverse ones, like side effects. Through pharmacology education, healthcare providers learn how to prescribe medications safely and effectively.
This education encompasses understanding drug interactions, the significance of drug metabolism, and the way drugs are absorbed by the body. Knowing these facets can help predict potential side effects or adverse reactions, aiding in providing better patient care. It underscores the significance of personalized medicine, where knowledge about an individual's reaction to a drug can be used to tailor treatment plans to minimize risks and maximize benefits.

• Safe prescription practices
• Drug interaction awareness
• Understanding patient-specific responses

Doxycycline Photosensitivity

Doxycycline is a widely used antibiotic, often prescribed for infections like chlamydial urethritis. One of its well-known side effects is photosensitivity. This means that patients taking doxycycline may develop skin rashes or burns after even limited exposure to sunlight. This reaction occurs because doxycycline can make the skin more sensitive to UV light.
To manage this side effect, patients are usually advised to take precautions when outdoors. This includes using sunscreen, wearing long sleeves and hats, and avoiding sun exposure during peak hours. Recognizing the potential for photosensitivity is essential for anyone taking doxycycline, as it allows them to take proactive steps to prevent discomfort.
Ultimately, being mindful of doxycycline's photosensitivity side effect helps ensure the medication treats the infection effectively, without causing additional skin complications.