Dr. Milind R. Shah
Chairman, Rural Obstetrics Committee, FOGSI
E-mail: manjus@sancharnet.in, drmilindshah@gmail.com
In this event of pandemic of Swine flu, lot of discussion taking place about Swine flu in pregnancy as well as various drugs used for it.
As pregnant women are susceptible for severe complications as we see in any other viral infections, there is lot of concern about prophylactic use of drugs like Tamiflu during pregnancy. In pregnancy, there is more possibility of dehydration, pneumonia or premature labor as hormonal changes during pregnancy depress the immune system to protect the fetus.
In the event of a pandemic, drugs like Oseltamivir will be used for treatment or prophylaxis in pregnant women, either by choice or because the women don’t know they are pregnant.
There is currently no reliable information on effects of this drug on a developing fetus, as we have not faced this problem before this.
The FDA has categorized this drug under the medical category “C”. The data collected is insufficient to give a clear picture on the effects of Tamiflu on pregnant women and her developing fetus. As there were no human specimens the initial tests were conducted on rats and later on rabbits. Maternal toxicity was minimal in rats while in rabbit showed slight maternal toxicities. Skeletal abnormalities were observed in the cases where the doses were increased to 500 mg per kg of body weight per day.
A similar study was conducted on rats and rabbits for the effects of Tamiflu in lactating mothers. It was observed that Oseltamivir and Oseltamivir carboxylate are given out in the milk. A similar human study could not be conducted due to the lack of lactating mothers infected by the flu who are willing to contribute towards experimentation.
The conclusion of these studies was “Tamiflu should be prescribed to a pregnant woman only if the case justifies the potential benefit of the fetus.”
Tamiflu (Oseltamivir) and Relenza (Zanamivir) are in the same class of drugs. But Tamiflu is a pill and liquid, while Relenza is a powder form that needs to be inhaled.
The main ingredient of the Tamiflu is the Oseltamivir phosphate, which belongs to group neuraminidase inhibitors. It acts by attacking the influenza virus in the body and stops it from spreading inside the body.
Each capsule of the medication contains seventy-five grams of the active drug. Recommended dosage is two capsules orally, one capsule in the morning and one in the evening for five days. For women who have been exposed to the influenza virus and who are taking this medicine as a preventive measure against the flu should take only one capsule in a day for seven days.
The Center for Disease Control and Prevention, (CDC) says that because a test result for the new H1N1, “Swine Flu” flu can take days, Tamiflu should be given to any pregnant patient with flu symptoms combines with likely contact with someone else with Swine Flu. Its known fact that this drug acts only if started early after contracting flu it need to be used despite not being recommended in pregnancy because the benefit of giving Tamiflu outweighs the risk. Simultaneously correction of hydration and treatment of fever with suitable antipyretics and adequate rest doesn’t need more emphasis.