Published Feb 24, 2026 | 7:00 AM ⚊ Updated Feb 24, 2026 | 7:00 AM
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Synopsis: CDSCO has ordered new warnings on two widely used medicines — doxycycline and carbimazole — after adverse reactions were flagged. Doxycycline must now carry cautions about restlessness, anxiety, irritability, nervousness, and dizziness. Carbimazole labels will warn of agranulocytosis, a potentially fatal drop in white blood cells. Manufacturers must update inserts, with patients advised to stay vigilant.
CDSCO orders new warnings on doxycycline, the common antibiotic, and carbimazole, the thyroid medicine — here is what patients need to know
India’s Central Drugs Standard Control Organisation (CDSCO) has issued directives ordering pharmaceutical manufacturers to update the warning labels on two widely used medicines, the antibiotic doxycycline and the thyroid drug carbimazole, after the country’s drug safety monitoring system flagged adverse reactions that were not previously listed in Indian prescribing information.
The orders, signed by Drugs Controller General of India Dr Rajeev Singh Raghuvanshi and addressed to all State and Union Territory licensing authorities, follow a process that began at the 26th Signal Review Panel convened by the Pharmacovigilance Programme of India (PvPI) in March 2025.
Doxycycline is one of the most commonly prescribed antibiotics in India. Doctors reach for it when treating chest infections, acne, urinary tract infections, typhus, and leptospirosis. It is also given to people travelling to malaria-prone areas as a preventive medicine.
In short, it is the kind of antibiotic that a large cross-section of the Indian population, from young adults battling stubborn acne to labourers in flood-affected regions at risk of leptospirosis, is likely to have taken at some point.
The new concern is about the brain and nervous system. Patients on doxycycline have been reporting feelings of restlessness, anxiety, irritability, nervousness, and dizziness. These are not dramatic, headline-grabbing reactions, but for someone who does not know the drug can cause them, they can be distressing and confusing, particularly if a patient is already unwell.
CDSCO has now directed that these CNS (central nervous system) side effects be listed not just in the adverse reactions section of the prescribing leaflet, but also in the caution section, meaning doctors and patients must be actively warned before starting the medicine, not merely informed after the fact.
“Manufacturers of doxycycline formulations are directed to mention CNS side effects, restlessness, anxiety, irritability, nervousness, and dizziness, as an adverse drug reaction in the caution section of the package insert and promotional literature of the drug,” the CDSCO letter stated.
Carbimazole is a medicine used to treat an overactive thyroid gland — a condition called hyperthyroidism. When the thyroid produces too much hormone, it can cause a racing heart, weight loss, tremors, and anxiety. Carbimazole works by slowing down the thyroid’s hormone production.
It is commonly prescribed to patients with Graves’ disease, which is one of the most frequent causes of hyperthyroidism, and tends to affect women more than men, often in their thirties and forties.
The risk flagged here is far more serious. Agranulocytosis is a condition in which the body’s white blood cell count drops dangerously low, leaving the immune system nearly defenceless against infection. A patient experiencing agranulocytosis can develop severe infections very rapidly, and without prompt medical attention, the condition can be fatal.
Warning signs typically include a sudden high fever, sore throat, and mouth ulcers, symptoms that can easily be mistaken for a routine illness.
The association between antithyroid drugs and agranulocytosis has been known internationally for decades and is listed in prescribing information in many countries. India’s directive now formally brings domestic labelling in line with global standards.
“Manufacturers of carbimazole formulations are directed to mention agranulocytosis as an adverse drug reaction in the prescribing information leaflet and promotional literature of the drug,” the CDSCO letter stated.
Both concerns were first raised through India’s national pharmacovigilance system, which collects Individual Case Safety Reports, essentially, documented accounts of patients experiencing unexpected reactions to medicines. These reports are reviewed by the National Coordination Centre for PvPI, housed at the Indian Pharmacopoeia Commission in Ghaziabad.
The signals for both drugs were discussed at the 26th Signal Review Panel on 24 March 2025. From there, the recommendations went to separate specialist committees.
The Expert Committee on Antimicrobial and Antiparasitic Agents reviewed the doxycycline case on 8 January 2026, while the Expert Committee on Endocrinology and Metabolism reviewed the carbimazole case on 6 January 2026. Both committees endorsed updating the labels, and CDSCO issued the formal directives to state authorities shortly after.
State and UT drug licensing authorities are now required to instruct every manufacturer of these two medicines operating under their jurisdiction to revise their package inserts and promotional materials accordingly. They have been asked to confirm compliance back to CDSCO’s Post Marketing Drugs Safety Monitoring Division in New Delhi.
For patients already taking either medicine, the immediate practical advice is straightforward: if you are on doxycycline and notice unusual anxiety, restlessness, or dizziness, mention it to your doctor. If you are on carbimazole and develop a sudden fever, sore throat, or mouth ulcers, seek medical attention promptly do not wait and see.
