Treatments
Hyperemesis gravidarum is a biological condition with a genetic basis.
Unfortunately there is a persistent belief - even among some healthcare providers - that medication to treat nausea and vomiting should not be used in pregnancy. This is not true and leads to a significant amount of suffering when treatment for severe symptoms is refused. It can also increase the risk of severe complications of HG.
While it's understandable that you may be reluctant to take medications during pregnancy, it's important to understand that with HG there is no risk-free option, and HG can be dangerous both for you and for your pregnancy.
There are a variety of safe treatments available and there are guidelines doctors can follow for prescribing them. How effective the treatments are can vary from person to person - and even from pregnancy to pregnancy for the same person. The goal of medications is to help to control and manage symptoms: for most of us, the treatments will not totally eliminate symptoms. They may help reduce the symptoms to "normal" nausea and vomiting; and for some the goal may be simply to keep you from needing hospital treatment as often as before.
The below information covers some of the more common medication treatments for HG in the HSE guidelines, as well as some common queries that patients ask in our support group. As always, ask your own doctor or pharmacist about what's right for you. We also have a guide to getting the most from your time with healthcare providers, which you may find helpful.
In addition to anti-emetic medication, it is important to correct dehydration with an IV drip if you can't manage to drink or keep fluids down.
First-line medication: Cariban
This is one brand name for doxylamine (an antihistamine) and Vitamin B6 (pyridoxine). It is available in different countries under different brand names e.g. Nuperal (Italy, Greece), Navalit (Belgium, Netherlands), Xonvea (UK), Nausefe (Portugal). Doxylamine alone is available over-the-counter in some countries, though not in Ireland.
Cariban is a well-established medication for nausea and vomiting and hyperemesis, one of the most extensively used medications in pregnancy, and there are no known safety concerns. For this reason it is the first-line treatment in Ireland - but it's not necessarily the most effective.
For some women it will work well and they won't need any other medications. For others, Cariban needs to be combined with additional medications (see below) or it doesn't work. As one of the active ingredients is an antihistamine, some patients feel very tired or drowsy while taking it.
As of 1st August 2024, Cariban is licensed and available on the medical card/Drugs Payment Scheme like other medication (read more about our HG2Costly campaign which made this change here).
If Cariban isn't working well enough for you, or isn't accessible, you should ask about the second line medications.
Second-line: Phenergan, Valoid, Stemetil.
These are brand names for different antihistamines (promethazine, cyclizine, prochlorperazine). Phenergan and Valoid are more well-studied than Stemetil, but there are no known safety concerns with any of them. Similar to Cariban, they can make some patients feel tired or drowsy. They can usually be taken with Cariban: if you are doing this, stagger the time you take medications so that you are taking a dose every 2-3 hours e.g.; Cariban at 7am, Valoid at 10am, Cariban at 1pm, Valoid at 4pm, etc.
Stemetil is often given in hospitals in Ireland as an injection, and is also available in tablet form or as a dissolvable tablet (Buccastem).
Adding a PPI medication like omeprazole can also help reduce your symptoms, in combination with other medications.
Third-line: Ondansetron
Ondansetron (brand name Zofran in some countries) is a different type of medication called a serotonin antagonist, and can be very effective (it is also commonly used for chemotherapy nausea, and nausea during or after surgeries).
Some doctors are reluctant to prescribe ondansetron because of concerns about potential birth defects, particularly cleft lip and palate, and heart defects. However, evidence of any connection is not proven. If it exists, may be due to HG itself rather than ondansetron (as we say, there is no risk-free option with HG!).
The UK Teratology Information Service says:
The available evidence shows that the vast majority of babies exposed in the womb to ondansetron do not have these birth defects. Ondansetron used after around week 10 of pregnancy would not be able to cause these problems as the baby is fully developed by this stage.
The Irish Medicines in Pregnancy service supports use of ondansetron to treat HG :
IMPS does not consider that currently available data support the conclusion that ondansetron causes congenital anomalies.... The available data on ondansetron safety should facilitate the provision of more detailed and accurate counselling to pregnant women regarding potential risks of ondansetron use during pregnancy. These potential risks should be balanced with the benefits of managing a severe underlying maternal condition that can also lead to a range of adverse pregnancy outcomes.... IMPS recommends that ondansetron should still be considered a valid treatment option for select women with hyperemesis gravidarum in whom first-line treatments have failed.
Based on the above, it is reasonable to wait til after 10w gestation to take ondansetron. However if other medications have not worked well enough, it is also reasonable to start ondansetron as early as needed.
Common side-effects include headache, and constipation. Constipation can be severe if not managed, sometimes needing hospital treatment, and the usual dietary advice for pregnancy is often not possible with HG. If you are able to eat, fibre supplements or ground flaxseed added to foods can be helpful.
We advise anyone taking ondansetron to ask their pharmacist or doctor about both over-the-counter (e.g.: Lactulose, Fybogel) and prescription treatments (e.g.: Movicol) to combat constipation. Some of these are flavoured powders mixed into water; it may be more difficult to consume if you are struggling to drink water or much liquid.
Be sure to tell your doctor about any other medications you are taking before you take ondansetron - especially if you take anti-depressants or migraine medications, as some types can interact with ondansetron and in rare cases, contribute to a serious condition called serotonin syndrome.
All of the second- and third-line medications above are available from your GP, under the Drugs Payment Scheme and medical card.
Other medications
If the above treatments are not working, steroids are usually the next option discussed. Your GP would usually refer you into hospital, if they haven't already, to discuss these.
