7 mistakes in taking emergency contraceptive pills

 

The drug levenogestrel (Postinor) which is taken to prevent sudden pregnancy is widely used in Sri Lanka. But many people, including doctors, are not exactly aware of how this medicine works and the cases of its failure, so many people are not able to take this medicine safely. In a previous article, we  informed you about the ways to prevent sudden pregnancy. The purpose of this article is to explain the risk of pregnancy even after taking Levogestrel (Postinor) after unprotected sex.

Chances of becoming pregnant even after using emergency contraception.

 1. Taking medication more than 72 hours after unprotected sex.

According to the latest medical data available, this drug should be taken within a maximum of 96 hours after unprotected sex to be effective. Getting the medication as soon as possible increases success.

2. Taking medicine during last 14 days of menstrual cycle

This medicine works by preventing or delaying the release of an egg from a woman's ovaries for a few days. Sperm deposited in the vagina remain alive for about five days. But because this drug delays ovulation, those sperm do not get a chance to fertilize an egg. However, if an ovum has been released at the time of taking the medicine, emergency contraceptive pills are not able to prevent the ovum from joining with the sperm and fertilizing it. Then a pregnancy will occur and the fetus will not be aborted due to these drugs.

3. Taking levogestrel when a pregnancy has already occurred  .

These drugs cannot prevent a fertilized egg from implanting in the uterus or cause an abortion. If fertilization has occurred due to previous intercourse, levenogestrel will not be effective.

4. Having unprotected sex again after taking the medicine. 

Ovulation can occur as early as 5 days after taking levenogestrel. If intercourse takes place again at that time, there is a possibility of pregnancy.

5. Excretion of the medicine with vomiting. 

The drug may cause side effects such as vomiting and nausea. If vomiting occurs within 2-3 hours after taking the emergency contraceptive pill, it is necessary to take the medicine again.

6. Obesity

If the woman's BMI is above 26, the usual dose of Levogestrel 1.5 mg is not enough to prevent ovulation. In such a case, the medicine needs to be taken in a higher dose.

7. Enzyme inducing drugs.

Women taking drugs like  griseofulvin, rifampicin, carbamazepine, which stimulate liver enzymes,  cannot prevent ovulation with the normal dose of the drug. Therefore, women who take these drugs need to take the drug in higher doses

 

Even if emergency contraceptive pills are used correctly without any of the above reasons, there is a small risk of pregnancy. Therefore, if menstruation does not occur normally within three weeks of having unprotected sex, it is appropriate to find out whether pregnancy is possible through a urine test. 

Understanding Enzyme-Inducing Drugs: Implications for Medication Management

 In the realm of pharmacology, the interaction between drugs is a complex puzzle that healthcare providers must navigate diligently to ensure optimal patient care. Among the various factors influencing drug interactions, the phenomenon of enzyme induction stands out as a critical mechanism with profound implications for medication management. Enzyme-inducing drugs have the capacity to modulate the activity of specific enzymes in the body, thereby altering the metabolism and effectiveness of concomitantly administered medications. This article explores the mechanisms, clinical significance, and practical considerations associated with enzyme induction in pharmacotherapy.

 

 Mechanisms of Enzyme Induction:

 To grasp the concept of enzyme induction, it is essential to understand the role of enzymes in drug metabolism. Enzymes, particularly those housed in the liver's cytochrome P450 (CYP) system, play a pivotal role in metabolizing drugs and xenobiotics. Enzyme-inducing drugs exert their effects by activating nuclear receptors, such as the pregnane X receptor (PXR) and the constitutive androstane receptor (CAR). Upon activation, these receptors initiate a cascade of events leading to increased transcription and synthesis of drug-metabolizing enzymes, notably the cytochrome P450 enzymes.

 

 Clinical Significance:

 The clinical significance of enzyme induction lies in its potential to alter the pharmacokinetics and pharmacodynamics of co-administered drugs. By accelerating the metabolism of substrates processed by induced enzymes, enzyme-inducing drugs can lead to reduced plasma concentrations and therapeutic efficacy of affected medications. This phenomenon poses a substantial risk in various clinical scenarios, particularly when managing chronic conditions requiring multiple drug therapies.

 

 Examples of Enzyme-Inducing Drugs:

 Several medications are recognized for their capacity to induce drug-metabolizing enzymes, thereby precipitating clinically relevant drug interactions. Phenytoin, a commonly prescribed antiepileptic agent, is renowned for its potent enzyme-inducing properties. By upregulating cytochrome P450 enzymes, particularly CYP3A4 and CYP2C9, phenytoin accelerates the metabolism of numerous drugs, including oral contraceptives and warfarin. Consequently, patients concurrently taking phenytoin and these medications may experience reduced contraceptive efficacy or compromised anticoagulant effects, necessitating dosage adjustments or alternative contraceptive measures.

 

Similarly, carbamazepine, another antiepileptic drug, exhibits prominent enzyme-inducing effects predominantly on CYP3A4 and CYP2C19 enzymes. This property renders carbamazepine a potential culprit in drug interactions with a wide array of medications, ranging from antipsychotics to antidepressants and oral contraceptives. Moreover, rifampin, a cornerstone in the treatment of tuberculosis and other bacterial infections, induces cytochrome P450 enzymes and can significantly impact the metabolism of various drugs, necessitating vigilant monitoring and dosage adjustments to ensure therapeutic efficacy.

 

 Clinical Implications and Considerations:

 The ramifications of enzyme induction extend beyond drug interactions to encompass therapeutic failure, compromised patient outcomes, and increased healthcare costs. Healthcare providers must remain vigilant in recognizing and managing potential interactions involving enzyme-inducing drugs. Comprehensive medication reconciliation, diligent review of patient medication profiles, and patient education are imperative to mitigate the risks associated with enzyme induction.

 

Moreover, interdisciplinary collaboration between pharmacists, physicians, and other healthcare professionals is paramount in optimizing medication management strategies. Utilization of electronic prescribing systems equipped with drug interaction alerts and decision support tools can aid healthcare providers in identifying and mitigating potential interactions proactively.

 

 Conclusion:

 In conclusion, enzyme induction represents a crucial determinant of drug interactions with far-reaching implications for medication management. Understanding the mechanisms and clinical significance of enzyme induction is essential for healthcare providers to navigate the complex landscape of pharmacotherapy effectively. By embracing a proactive approach to medication management, healthcare providers can minimize the risks associated with enzyme-inducing drugs, thereby ensuring optimal therapeutic outcomes and patient safety.