Research on HG's short- and long-term effects is desperately needed and needed now. We need to do more to find a cure for this disease that has such devastating effects on a growing number of soon-to-be mothers.
Common Medications
Although no drug is generally encouraged and few are considered completely safe during pregnancy, the risk of these medications must be balanced against the potential complications associated with prolonged starvation and dehydration. These both present risks for both mother and child. Focusing on treating the individual symptoms and easing the incredible misery of HG are top priorities.
To look up a drug for more information about its use or safety:
Important Note: The class of drugs known as serotonin antognists (Zofran/ondansetron, Anzemet/dolasetron, Kytril/granisetron) are dose-dependent drugs. Both benefits and side-effects increase with the dose. They are similar, yet do not have the exact same results in all women. Please note that some women with nausea/vomiting improve greatly on the higher doses, thus avoiding IV's and expensive nutritional therapies. Gradual reduction in dose, then frequency is critical to avoid relapse. It's important to intervene early with effective medications in women who show a clinical course that may lead to hyperemesis, or in women who have a history of HG.
Remember: Individual responses to medications vary greatly. There is no single isolated cause or "cure" for the nausea and vomiting in all women. Treatment should focus on the primary triggers of nausea/vomiting such as motion sensitivity. If there are numerous triggers, medications that directly target the vomiting center in the brain (serotonin antagonists) are likely most effective. If a woman is vomiting constantly, oral dosing of medications may not be effective. A few doses IV followed by a trial of oral medication is important. Women often report a medication is not working orally, but will if given IV or subcutaneously.
Mother's Note: If you have pre-existing medical conditions (diabetes, heart disease, etc.), a history of medication reactions, or are a smoker, please inform your physician before taking medications.SEROTONIN ANTAGONISTS
Highly selective antagonist of 5-HT3 receptors in the vagus, CTZ (chemotrigger zone) and gut. Mostly Class B drugs.
Possible side-effects: Headache, mild liver function abnormalities,
constipation*, diarrhea
* Bowel management is very important. For information on managing these symptoms, download this article (1.34 Mb PDF).
Often effective in mothers who have multiple triggers (smell, motion, etc.), a history of hormone sensitivity, and/or moderate to severe vomiting. If a woman has a history of HG that responded to serotonin antagonists, it should be used early and as a first line drug to minimize severity.
IMPORTANT: Effects are dose dependent. Expensive intravenous therapies may sometimes be avoided if higher doses are used. Best taken on a strict schedule and weaned very slowly when asymptomatic for over two weeks. It is not uncommon for women to require this medication until delivery. Different brands may have different effects.
| Drug Name | Min/Max Dosage | Notes | Research Studies |
| Zofran (Ondansetron) |
4 to 8 mg IV/orally every 6
hours Sometimes given via SQ pump. Some women require dosing until late pregnancy or delivery to avoid relapse or an increase in symptoms. |
Very expensive. Patient
assistance program available. |
Pre-emptive
therapy for severe nausea and vomiting of pregnancy and hyperemesis
gravidarum. The safety of ondansetron for nausea and vomiting of pregnancy: a prospective comparative study. Treatment of hyperemesis gravidarum with the 5-HT3 antagonist ondansetron (Zofran). Treatment of intractable hyperemesis gravidarum by ondansetron. Serotonin receptor physiology: relation to emesis A pilot study of intravenous ondansetron for hyperemesis gravidarum. Pharmacokinetics of Three Formulations of Ondansetron |
| Kytril (Granisetron) |
1 mg every 12 hours (IV or orally) Allows twice a day dosing Also available in transdermal patch form as Sancuso. |
Very expensive. Patient
assistance program available. Kytril is now available as a generic.  | No research on its use for HG |
| Mirtazapine (Remergil, Remeron) | May interact with sedatives,
antihistamines, and tricyclic antidepressants. Has both anti-vomiting and anti-depressant effects. |
Rohde A, et al. Mirtazapine (Remergil) for treatment resistant hyperemesis gravidarum: rescue of a twin pregnancy. Mirtazapine use in resistant hyperemesis gravidarum: report of three cases and review of the literature. | |
| Aloxi (palonosetron) |
Dose not established in HG. 0.25 mg IV given for chemo. | Half-life: 40 hr. & only
given once in 5 days. Reimbursement Support Network. |
No research on its use for HG or pregnancy. |
| Anzemet (Dolasetron) |
Dose not established in HG. 50-150 mg orally daily is reported. | Slightly less expensive than
similar drugs. Patient assistance program available. |
No research on its use for HG |
CORTICOSTEROIDS
Cortisone/Corticosteroids - Not recommended until after 8-10 weeks
Some possible side-effects include weight loss, nausea and vomiting.
Steroids are used for refractory hyperemesis gravidarum; however, there is some concern over fetal brain development with prolonged dosing at high levels and use during the first trimester. No studies have proven a link and the HER Foundation has not heard such reports from women with HG. The typical treatment is a steroid burst with a rapid taper similar to what is used in acute asthma attacks. [Most studies of asthma patients using steroids show no adverse fetal effects.]
Women with hypothyroidism may have an
exaggerated response to corticosteroids; thus any steroid should
be used with caution in these mothers. Also, women with Type
1 Diabetes may require as much as a 40% increase in their insulin
when high dose steroids are started.
Complications including reduced birth weight, increased risk of
preeclampsia, and increased risk of oral and lip clefts have
been reported when corticosteroids were administered during
early pregnancy. However, the Collaborative Perinatal Project monitored
50,282 mother-child pairs, 34 of which had first-trimester exposure
to cortisone. No evidence of a relationship to congenital defects
was observed. If these drugs are used during pregnancy, the potential
risks should be discussed. Babies born to women receiving large
doses of corticosteroids during pregnancy should be monitored for
signs of adrenal insufficiency and appropriate therapy initiated,
if necessary.
Drug Classification:
Methylprednisolone is classified as pregnancy category C. Prednisone
is classified as category B but cortisone is classified as pregnancy
category D. This probably reflects the fact that cortisone is
more commonly used during pregnancy than is prednisone and therefore,
more reports of problems have been associated with cortisone
than prednisone, and not the fact that it is a more potent teratogen.
Corticosteroids cross the placenta. [From: Clinical Pharmacology
2000]
(See below for FDA-Assigned Pregnancy Categories for Drugs)
Research Links:
- Termination is not the treatment of choice for severe hyperemesis gravidarum: Successful management using prednisolone (130 Kb downloadable PDF)
- PubMed
Listing »
View more research abstracts about hyperemesis gravidarum and steroid therapy.
| Drug Name | Min/Max Dosage | Notes | Research Studies |
| Medrol or Solu-Medrol (Methylprednisolone or Prednisone) | Typical oral dosage is 48 mg
per day for three to five days, followed by slow tapering over two
to three weeks. Limit to one month of therapy if possible. See Goodwin article on right for more on dosing. |
Consideration should be given to using with serotonin antagonists and/or during weaning from steroids to prevent relapse. | T. Murphy Goodwin, MD Corticosteroid therapy in hyperemesis gravidarum Moran P, Taylor R. Management of hyperemesis gravidarum: the importance of weight loss as a criterion for steroid therapy. Nelson-Piercy C, et. al. Randomised, double-blind, placebo-controlled trial of corticosteroids for the treatment of hyperemesis gravidarum. |
ANTIHISTAMINES
Common side-effects: Drowsiness, dry mouth, blurred vision, constipation,
urinary retention, restlessness, insomnia, sedation, upset stomach,
nervousness, headache.
Mostly Class B drugs
Effective for MILD cases of nausea and vomiting during pregnancy or as adjunctive therapy with more potent medications. Women mostly sensitive to motion may benefit most. Antihistamines with sedative effects can be helpful for sleep.
Research Links:
- Gideon Koren, MD, FRCPC
Antihistamines are safe during the first trimester.
| Drug Name | Min/Max Dosage | Notes | Research Studies |
| Bonine, Antivert, Marezine (Meclizine/Buclizine/Cyclizine) |
Follow directions on the label. | See Medline Plus | |
| Dramamine (Dimenhydrinate) |
50-100 mg every 4-6 hours | Used for motion sickness. | |
| Doxylamine (Unisom) |
25 mg orally at bedtime, 1/2 tablet every 6 hours as needed |
Component of Bendectin/Diclectin. Often taken with vitamin B6. |
|
| Diclectin (doxylamine plus pyridoxine) |
Average dose is 1 tablet in
morning, one in afternoon and two at night. May be given in higher doses up to 12 tablets daily - see research links on right. |
Differs from Unisom/B6 combo
because it is a delayed release formula. Available only in Canada at present. Contact Murray Shore Pharmacy in Canada if you have a prescription and live in the US. |
C. Ineke Neutrel. Variation in rates of hospitalization for excessive vomiting in pregnancy by Bendectin/Diclectin use in Canada. Steven H. Lamm. The epidemiological assessment of the safety and efficacy of Bendectin. Atanackovic G, et. al. The safety of higher than standard dose of doxylamine-pyridoxine (Diclectin) for nausea and vomiting of pregnancy. |
| Benadryl (Diphenhydramine or Gravol) |
25 mg IVP/orally every 4–6 hours | ||
| Tigan (Trimethobenzamide) |
25 mg orally every 6-8 hours 200 mg IM every 6-8 hours |
||
| Vistaril, Atarax (Hydroxyzine) |
25 mg orally every 6 hours | Syrup available Helpful for insomnia |
ANTIDOPAMINERGICS: PHENOTHIAZINES
Common side-effects: Drowsiness, hypotension, dry mouth, constipation,
urinary retention, rash, extrapyramidal symptoms (EPS), restlessness,
confusion, fatigue.
Mostly Class C drugs.
May be helpful in mild and moderate cases or used in conjunction with other medications. Consider co-administration of antihistamines to minimize side-effects.
(Extrapyramidal symptoms include: involuntary movements, tremors and rigidity, body restlessness, muscle contractions and changes in breathing and heart rate.)
| Drug Name | Min/Max Dosage | Notes | Research Studies |
| Compazine, Stemetil (Prochlorperazine) |
5–10 mg orally, IM, or
IV every 6–8 hours Rectal 25 mg every 6–8 hours |
Risk of EPS additive with metoclopramide (Reglan). Treat EPS symptoms with Benadryl (can prophylax with Benadryl). Phenothiazines lower seizure threshold. | |
| Phenergan (Promethazine) |
12.5–25 mg IVP/orally, IM/PR every 4-6 hours | Warning: IV or injected doses can cause tissue damage. More info available on fda.gov. Side-effects common and may limit use. |
|
| Thorazine (Chlorpromazine) |
12.5–25 orally/IM every
4–6 hours Rectal 50–100 mg every 6–8 hours |
May increase risk of fetal malformations. May cause muscle spasms in neck/face and/or difficulty with speech. |
|
| Haldol (Haloperidol) |
1–2 mg orally/IM every 8 hours | Extrapyramidal symptoms (EPS) more common. May cause constipation. |
ANTIREFLUX MEDICATIONS
Common side-effects: Headache, dizziness, difficulty sleeping, constipation, diarrhea.
This class of drugs is helpful both for reflux and for prevention of gastric irritation which worsens nausea. They should be considered whenever a woman is vomiting frequently and/or cannot eat and drink sufficiently. Studies suggest they are safe during pregnancy. Mostly Class B drugs. [This list is not inclusive of all medications available.]
Research Links:
- Ruigomez A, et. al.
Use of cimetidine, omeprazole, and ranitidine in pregnant women and pregnancy outcomes.
- Arieh Lalkin, et. al.
Acid-suppressing drugs during pregnancy.
- Drugs & Therapy Perspectives
Gastro-oesophageal Reflux During Pregnancy: Treat With Care.
| Drug Name | Min/Max Dosage | Notes | Research Studies |
| Zantac (Ranitidine) |
50 mg IV every 8 hours or 150 mg orally daily or twice a day | ||
| Tagamet (Cimetidine) |
Not recommended during pregnancy due to antiandrogenic effects in humans. | Illinois Teratogen Information
Service Gastroesophogeal Reflux (GERD) Medications in Pregnancy |
|
| Pepcid (Famotidine) |
20 mg IVP/orally every 12 hours | ||
| Prevacid (Lansoprazole) |
30-60 mg/day | Bruce T. Vanderhoff, M.D, et.
al. (AAFP) July 15, 2002 Proton Pump Inhibitors: An Update. Nikfar S, et. al. Use of proton pump inhibitors during pregnancy and rates of major malformations: a meta-analysis. |
PROKINETIC AGENTS
Reglan blocks dopamine receptors in the CTZ (chemoreceptor trigger zone) and increases the CTZ threshold & decreases the sensitivity of visceral nerves that transmit afferent impulses from the GI tract to the vomiting center.
May be helpful in women who typically vomit after eating/drinking.
Their main symptoms often are GI specific (v. motion sickness or
sensitivity to light/sound) and these women may or may not respond
to other medications such as Zofran. These drugs are sometimes
used in conjunction with meds such as Zofran. Use with antihistamines
to minimize side-effects. Side-effects are very common and can be severe, especially when given quickly through an IV.
Common side-effects: Drowsiness, dizziness, abdominal pain, diarrhea,
restlessness, EPS, depression
(Extrapyramidal symptoms include: involuntary movements, tremors and rigidity, body restlessness, muscle contractions and changes in breathing and heart rate.)
| Drug Name | Min/Max Dosage | Notes | Research Studies |
| Reglan or Maxeran (Metoclopramide) |
10–20 mg IV/orally every
6 hours May be given orally, SQ pump, IV |
FDA recommends this drug be taken for up to 12 weeks. Risks of serious side-effects increase thereafter.
Additive CNS side effects when used with phenothiazines. Side-effects common and may limit use. Class B drug. |
L. Buttino Jr., et. al. Home subcutaneous metoclopramide therapy for hyperemesis gravidarum. Mati Berkovitch The safety of metoclopramide during pregnancy L. Buttino Jr., et. al. Home Infusion of Reglan |
| Propulsid (Cisapride) |
10 mg orally every 6 hours, before meals and at bedtime (maximum dose 20 mg every 6 hours) | No CNS side effects. Limited availability in US. |
ANTICHOLINERGICS/ANTISPASMODICS
Common side-effects: Confusion; dizziness, lightheadedness (continuing) or fainting; eye pain; skin rash or hives.
Should not be used in treatment of hyperemesis gravidarum. These agents slow gastric emptying and prolong GI transit time. Since slowed gastric emptying is part of the etiology of HG, these agents are inappropriate.
| Drug Name | Min/Max Dosage | Notes | Research Studies |
| Scopolamine, Belladonna (Hyoscine Hydrobromide) |
MISCELLANEOUS
| Drug Name | Min/Max Dosage | Notes | Research Studies |
| Pyridoxine (Vitamin B6, Hexa-Betalin) |
20-75 mg/day | Paresthesias may occur if taken
in high doses. Doses up to 150 mg are being used. Note: reactions to vitamins are uncommon but possible. See article from Kuwata Y., et al. |
Kuwata Y., et. al. Serious adverse drug reaction in a woman with hyperemesis gravidarum after first exposure to vitamin B complex containing vitamins B1, B6 and B12. |
| Reprivex | 3 tablets daily | Each tablet contains 25mg of Vitamin B6 (as Pyridoxine Hydrochloride) and 100mg of Ginger Root PE 5% Gingerois (zingiber Officinalis) | This medication was introduced in 2006. A prescription is NOT required for this medication. |
| Ginger | 250 mg orally every 6 hours or a glass of ginger ale as needed | May be helpful in mild cases. | |
| Emetrol (Fructose, Dextrose, and Phosphoric Acid) |
One or two tablespoonfuls upon arising and every three hours as needed. | May be helpful in mild cases. | |
| Marijuana (Cannabis) or the pharmaceutical extract: Marinol (Dronabinol) |
Dose not established for HG. | Medical Marijuana is currently legal in the following states (US): Alaska, California, Washington, Oregon, Hawaii, Colorado, Arizona, Maine. | Eran Kozer, et. al. Effects of prenatal exposure to marijuana. International Association for Cannabis as Medicine Does cannabis/THC do harm to the fetus if it is used during pregnancy? Washington Hemp Education Network Cannabis Indications |
| Benzodiazepine Derivatives: Valium (Diazepam) |
Dose not established for HG. | Class D drug. | Ditto A, Morgante G, la Marca
A, De Leo V. Evaluation of treatment of hyperemesis gravidarum using parenteral fluid with or without diazepam. |
| Neuroleptic: Inapsine (Droperidol) |
Gerald G. Briggs Briggs (LBMMC) Hyperemesis Protocol |
Use with diphenhydramine to
avoid side-effects. Category C drug. |
Nageotte MP, Briggs GG, Towers
CV, Asrat T. Droperidol and diphenhydramine in the management of hyperemesis gravidarum. Gerald G. Briggs Droperidol-diphenhydramine for hyperemesis gravidarum. |
** IM = Intramuscular (injection)
** IV = Intravenous
** IVP = Intravenous push (injected into an IV)
** PR = Per rectum
** SQ = subcutaneous (injected under the skin)
FDA-Assigned Pregnancy Categories for Drugs (United States Classification)
- Category A
Adequate and well-controlled studies have failed to demonstrate a risk to the fetus in the first trimester of pregnancy (and there is no evidence of risk in later trimesters).
- Category B
Animal reproduction studies have failed to demonstrate a risk to the fetus and there are no adequate and well-controlled studies in pregnant women.
- Category C
Animal reproduction studies have shown an adverse effect on the fetus and there are no adequate and well-controlled studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks.
- Category D
There is positive evidence of human fetal risk based on adverse reaction data from investigational or marketing experience or studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks.
- Category X
Studies in animals or humans have demonstrated fetal abnormalities and/or there is positive evidence of human fetal risk based on adverse reaction data from investigational or marketing experience, and the risks involved in use of the drug in pregnant women clearly outweigh potential benefits.
Excerpted from Drug Information for the Health Care Professional, USP-DI, Volume 1A, 11th ed., 1991.
Updated on: Mar. 24, 2010
Beyond Morning Sickness 
The Proving Grounds