Acetaminophen (Paracetamol) Linked to Decreased Vaccine Response and Low Testosterone Level in Men

Acetaminophen side effects on pregnant women and children

             Acetaminophen also known as paracetamol outside the United States is one of the leading over-the-counter drug globally. Tylenol the leading brand of acetaminophen in the United States sold more than 330 million dollars in 2018. Acetaminophen is the most commonly used fever reduction for infants and a drug of choice for pain on pregnant women.

            Acetaminophen side effects are one of the researches that are constantly being conducted. Acetaminophen at a recommended dose has established its safety and efficacy but when acetaminophen maximum daily dose which 4 grams is exceeded and the usage is prolonged it could lead to liver damage. The FDA is now asking drug manufacturers to limit acetaminophen’s strength in prescription drug products to 325 mg per tablet or capsule making these products safer for patients.   

             In the United States acetaminophen overdose is the second most common cause of liver failure requiring transplantation and it has replaced hepatitis as the most common cause of acute hepatic failure. In Great Britain, acetaminophen overdose is the most common cause of liver failure requiring liver transplantation.

Acetaminophen overdose

            According to the American Academy of Pediatrics there is a very low incidence of toxic effects on children but acetaminophen toxicity remains a concern because it is used widely in children. Way back in 1997, a data collected by 66 US regional poison control centers, of 94 fatal acetaminophen overdose cases, 25% of it were associated with unintentional therapeutic error and intentional misuse thus it indicates the lack of understanding on the part of caretaker or patient regarding acetaminophen therapy.  Over the years a lot of researches about acetaminophen side effects and acetaminophen toxicity have been conducted. To avoid acetaminophen overdose in children, dosing should be based on weight of the child using 10-15 mg/kg/dose.

           

             A study published in the British Journal of Clinical Pharmacology on March 2018 revealed that unintentional overdose of acetaminophen happens during cold and flu season. A lot of people taking over-the-counter cold and cough remedies that contain acetaminophen take it routinely with Tylenol or other acetaminophen brands for pain or fever thus ingesting excessive amount.

           

Prophylactic acetaminophen in infants reduces vaccine response

            The Lancet published a research sponsored by Belgium based Glaxo Smith Kline Biologicals which showed that acetaminophen administration decreases antibody responses to several vaccine antigens. Investigators randomized healthy infants in the Czech Republic and involved more than 400 healthy infants who are received vaccines against Pneumonia and Influenza co-administered with a diphtheria, tetanus, acellular pertussis, hepatitis B, inactivated poliomyelitis, and Haemophilus influenzaetype b (Hib) conjugate vaccine and oral human rotavirus vaccines (prevention of diarrhea to infants and children caused by rotavirus which is the common cause of diarrhea in children and infants globally).

            The study concluded that administration of acetaminophen at the time of vaccination should not be routinely recommended since it reduces vaccine response.

Prenatal acetaminophen exposure and language delay in girls

            In a study published on European Psychiatry on January 2018, researchers from the Icahn School of Medicine at Mount Sinai found an increased rate of language delay in girls at 30 months born to mothers who used acetaminophen during their early pregnancy.  There were 754 women on their 8-13 weeks of pregnancy were enrolled into the study. The participants were asked to report the number of acetaminophen tablets they had taken between conception and enrollment and tested the acetaminophen concentration in their urine at enrollment.  Their child’s language milestone at 30 months were assessed by nurses and follow-up questionnaire completed by participants regarding their frequency of language delay which is defined as the use of fewer than 50 words. Those parents who took acetaminophen more than six times in their early pregnancy were nearly six times more likely to have language delay than girls born to mothers who did not take acetaminophen in their early pregnancy. 

            The Study concluded that the use of acetaminophen in pregnant women should limit their use of the analgesic during pregnancy. The study’s senior author, Shanna Swan, PhD, Professor of Environmental and Public Health at the Icahn School of Medicine at Mount Sinai stated that it is important to look at the language development because it has shown to be predictive of other neurodevelopmental problems in children.

High acetaminophen level in men may delay pregnancy

            Couples in which the male partner had high levels of acetaminophen in his urine took longer to achieve pregnancy than couples in which the male had lower levels of acetaminophen in his urine. Prolonged acetaminophen use may reduce testosterone produce in unborn baby boys; a research has found which was published at Science Translational Medicine on May 2015. The study was funded by the British Society of Paediatric Endocrinology and Diabetes, Wellcome Trust and the Medical Research Council. The authors found that a single acetaminophen therapeutic dose had no effect on testicular development but continued dosing of acetaminophen for a week could reduce fetal testosterone by 45 percent. The authors recommended that that the lowest effective dose of acetaminophen should be taken for the shortest possible time by pregnant women.

            It should be noted that these acetaminophen side effects can happen when not used with caution and be always reminded that a very high fever and pain in pregnancy could put the baby at risk. The preferred antipyretic is still acetaminophen. A pregnant woman should not take aspirin or ibuprofen, taking ibuprofen regularly in the first trimester may increase the chance of having miscarriage. The baby could also develop cleft palate, heart defect or defects in the abdominal wall. Though a single dose of ibuprofen at any stage of pregnancy is unlikely to cause the mother or the baby harm, it is still best to be cautious and stick with acetaminophen being far safer.

           

            Don’t be afraid to take acetaminophen but be cautious. Do not take acetaminophen when not needed and do not prolong the use. All drugs have side effects and acetaminophen which is considered to be a very safe drug is not an exception.

            Perhaps you can manage common pains such as back pain which is one of the most common among pregnant women, in non-pharmacological way and not take acetaminophen. You can always talk to your Doctor on whatever recommendations she/he may have.