Drugs Causing Erythroderma.

Drugs That Decrease T4 Absorption

Various classes of medications can significantly interfere with the absorption of levothyroxine (T4). This list details common agents that require special clinical attention when prescribed alongside thyroid hormone:

• ACE Inhibitors: Key examples include Captopril, Enalapril, and Quinapril.
• Antibiotics: A broad spectrum, including Amoxicillin, Ampicillin, Ciprofloxacin, Demeclocycline, Doxycycline, Minocycline, Nalidixic Acid, Nitrofurantoin, Norfloxacin, Penicillin, Rifampin, Streptomycin, Tetracycline, Tobramycin, Trimethoprim/Sulfamethoxazole (Septra + Bactrim).
• Anticonvulsants: Mainly Barbiturates and Carbamazepine.
• Antipsychotics (Phenothiazines): Perphenazine, Prochlorperazine, and Trifluoperazine.
• Antimalarials: Chloroquine and Hydroxychloroquine.
• Nonsteroidal Anti-inflammatory Drugs (NSAIDs): Medications such as Diclofenac, Diflunisal, Etodolac, Fenoprofen, Flurbiprofen, Indomethacin, Ketoprofen, Ketorolac, Meclofenamate, Mefenamic Acid, Naproxen, Phenylbutazone, Piroxicam, and Sulindac.
• Tricyclic Antidepressants: Include Amitriptyline, Desipramine, and Imipramine.

In addition to these categories, a wide variety of individual agents must be administered with caution:

Verapamil

It is essential that patients starting or stopping any of these treatments notify their endocrinologist to properly monitor TSH levels and adjust the levothyroxine dose if necessary. Separating the administration of T4 and these drugs, usually by several hours, is a common strategy to mitigate these absorption interactions.