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How Long Does Diclectin Take to Work?

Key Takeaways

  • Diclegis is a delayed-release medication used to treat nausea and vomiting of pregnancy (NVP).
  • It does not work immediately and is meant to build up over time, not relieve sudden nausea.
  • Most pregnant women notice improvement within 3 to 5 days when taken as directed.
  • Drowsiness is a common side effect, especially during the first trimester.

What Is Diclectin?

Diclectin is a brand-name, delayed-release tablet containing doxylamine succinate (an antihistamine) and pyridoxine hydrochloride (vitamin B6). It is approved by Health Canada for the treatment of nausea and vomiting of pregnancy and is manufactured by Duchesnay.

In the United States, the same combination is sold as Diclegis and is approved by the Food and Drug Administration (FDA). Diclectin was developed as a modern version of Bendectin, which was withdrawn decades ago despite later evidence showing no link to birth defects.

How Quickly Does Diclectin Start Working?

Diclectin does not provide immediate relief. Because it is a delayed-release tablet, the medication is designed to dissolve slowly and work over time rather than all at once.

Most patients begin to feel symptom improvement within 72 hours, though for some it may take up to 5 days to see results. It works best when taken before nausea becomes severe, rather than as an as-needed medication.

Why Diclectin Takes Time to Work

Diclectin relies on steady blood levels of doxylamine and vitamin B6 to reduce nausea signals in the nervous system. Unlike over-the-counter antihistamines such as diphenhydramine, it does not act quickly after a single dose.

Skipping doses or taking it inconsistently can delay improvement. For best results, it should be taken daily on an empty stomach, swallowed whole with a glass of water, and stored at room temperature.

Typical Dosing Timeline

Most treatment plans begin with a bedtime dose, as drowsiness is common. If symptoms persist, the dose may be increased gradually under the guidance of a health care professional.

Because Diclectin builds up over time, taking an extra dose for sudden nausea usually does not help and may increase side effects such as sleepiness or constipation.

Common Side Effects

The most common side effect of Diclectin is drowsiness or sleepiness, especially early in treatment. Other possible side effects include:

  • Dry mouth
  • Constipation
  • Stomach pain
  • Fatigue

Less common but serious reactions, such as an allergic reaction or an irregular heartbeat, require immediate medical attention.

Safety in Pregnancy and Breastfeeding

Diclectin has been extensively studied and is considered safe for use during pregnancy, including the first trimester. Large studies show no increased risk of birth defects or pregnancy complications compared with placebo.

Breastfeeding considerations should be discussed with a health care professional, as doxylamine may cause sedation in infants.

Diclectin vs Other Treatments

Diclectin is considered a first-line treatment for nausea and vomiting of pregnancy. Medications such as Zofran are sometimes used for severe nausea but are generally considered second-line options.

Diclectin is not available over the counter and should not be substituted with separate doxylamine or vitamin B6 supplements without medical guidance.

FAQs

How long does Diclectin take to start working?
Most pregnant women notice improvement within three to five days of taking Diclectin as directed. Because it is delayed-release, it does not work immediately after the first dose.

Does Diclectin work right away for morning sickness?
No, Diclectin is not designed for fast relief. It works best when taken consistently to prevent nausea rather than treat sudden symptoms.

Why does Diclectin cause drowsiness?
Diclectin contains doxylamine, an antihistamine that commonly causes sleepiness. This effect is usually strongest during the first few days of treatment.

What if Diclectin doesn’t work after several days?
If symptoms do not improve after five days, a health care professional may adjust the dose or consider additional treatments. Severe or persistent nausea may require further evaluation.

Can you miss a dose of Diclectin?
Missing a dose may reduce effectiveness since the medication relies on steady levels in the body. If a dose is missed, do not double the next dose as it can increase your risk of side effects.

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