<p><strong>Migraine/Headache</strong>: The onset or exacerbation of migraine, or development of headache with a new pattern that is recurrent, persistent, or severe requires evaluation of the cause because women with migraine may be at increased risk of stroke.<br />
<br />
Drug Interactions:</p>

<ul>
	<li>The effectiveness of progestin-only pills is reduced by hepatic enzyme-inducing drugs such as phenytoin, carbamazepine, barbiturates, rifampin, efavirenz, bosentan and herbal preparations containing St. John&rsquo;s Wort (hypericum perforatum ). This could result in unintended pregnancy or breakthrough bleeding. During concomitant use of Norgestrel and substances that may affect its efficacy, it is recommended that a nonhormonal back-up method of contraception (such as condom) be used in addition to the regular intake of Norgestrel Tablets. Use of a nonhormonal back-up method is recommeded for 28 days after discontinuation of substances that have led to induction of hepatic microsomal enzymes. For women receiving long-term therapy with hepatic enzyme inducers, another method of contraception should be considered.</li>
	<li>Effectiveness of progestin-containing hormonal contraceptives and emergency contraceptive ulipristal acetate may be decreased if progestin-containing hormonal contraceptives are used within five days after ulipristal acetate dosing. If a woman wishes to use Norgestrel Tablets after using ulipristal acetate, she should do so no sooner than 5 days after the intake of ulipristal acetate and she should use a reliable barrier method for subsequent acts of intercourse until her next menstrual period.</li>
</ul>

<p><strong>Gastrointestinal</strong>: Diarrhea and/or vomiting within 4 hours after taking a pill may reduce hormone absorption. Women should use of a nonhormonal back-up method of birth control (such as a condom or spermicide) during the next 48 hours.<br />
<br />
<strong>Interactions with Laboratory Tests</strong>: The following endocrine tests may be affected by Norgestrel Tablets use:</p>

<ul>
	<li>Sex hormone-binding globulin (SHBG) concentrations may be decreased.</li>
	<li>Total thyroxine concentrations may be decreased, due to a decrease in thyroid binding globulin (TBG). However, free thyroxine level should remain unchanged.</li>
</ul>