Medical Management of Ectopic Pregnancy with Methotrexate
Patients diagnosed with an asymptomatic ectopic pregnancy can now be offered several treatment options. Not all patients require surgery and many can be managed either expectantly or medically using Methotrexate. Trials are currently underway to compare medical versus expectant management, but use of methotrexate is currently widespread in many UK hospitals.
Patients suitable for methotrexate must be haemodynamically stable and fulfil the following criteria: • No previous history of liver disease, anaemia, leucopoenia, thrombocytopenia • Not currently breast feeding • Understand the need for surveillance and are willing to attend for regular tests • Unruptured ectopic Success rates of medical treatment tend to be better if • βhCG < 3000 iu/ml • tubal mass < 3.5 cm.
Dose of Methotrexate
Methotrexate is usually administered as a single intra muscular injection of 50 mg/ m2. Doses are usually capped at 100mg to reduce side effects. Hospital pharmacy departments will calculate the dose of the drug injection based on the patient’s height and weight.
Administration of Methotrexate
Methotrexate is administered by intra muscular injection. Methotrexate is a Cytotoxic agent and must be administered in accordance with strict local policy.
Patients should be given written information explaining the treatment and then give written consent prior to injection. The patient must made aware that future pregnancy should be avoided for 3 months following administration of Methotrexate.
The following tests are usually performed prior to injection to ensure safety Full Blood Count βhCG Liver Function Tests Urea and Electrolytes Group and Save – If patient is rhesus negative 250 iu/ml Anti-D will be administered prior to treatment
Advice and Follow Up
The treatment is generally very effective and less than 10% of women require surgery. Nearly 75% experience abdominal pain following treatment and this may require admission and a repeat ultrasound scan. 15% of patients require a second dose of Methotrexate. 7% of patients may experience tubal rupture whilst undergoing treatment.
Side effects include
The side effects of treatment include: conjunctivitis, stomatitis, gastro-intestinal upset, bone marrow suppression and increased abdominal pain. An increase in abdominal pain is not uncommon between day-3 and day-7 following Methotrexate injection and pain does not necessarily require surgical intervention if the patient remains clinically stable. However, these patients should be reassessed and their haemoglobin repeated. Patients with evidence of rupture or significant pelvic/abdominal tenderness should be discussed with an experienced Consultant and are likely to require surgical intervention.
Advice During treatment
Patients should be advised to: Avoid sexual intercourse To use reliable contraception for 3 months To avoid folic acid until treatment episode completed. Ensure adequate fluid intake Avoid exposure to sun Attend regularly for follow up Report any symptoms, including those suggestive of infection or bone marrow suppression e.g. fever, sore throat or any unexplained bleeding or bruising. Avoid NSAIDs Avoid alcohol Avoid herbal remedies N.B. Antibiotics such as Trimethoprim, Co-trimoxazole, Tetracycline, NSAIDs, diuretics and Hypoglycaemics can all potentiate the effects of Methotrexate and should be avoided where possible.
Monitoring during treatment
βhCG + FBC is usually taken on day 7 (day 1 = day on which Methotrexate is given). Day 4 bloods are sometimes also taken in some units as this gives an opportunity to assess and reassure the patient during the course of the treatment. It is not unusual to observe an increase in the βhCG level. Provided that the patient is clinically stable, the patient will have further bloods taken on Day 7. If βhCG levels have not fallen by more than 15%, a further dose of Methotrexate may be required. Bloods will then be repeated day 4 after this second dose and should be repeated every 7 days until levels βhCG reach <4 i.u/ml. The results should be discussed with a consultant if the rate of decline is less than 15% of the preceding level or the levels are > 25 iu/ml 3 weeks after the initial dose of methotrexate. If the rate of decline is sub-optimal, a third dose of Methotrexate may be administered or the patient may need surgical treatment.
Mr Patrick Bose
Consultant Obstetrics and Gynaecology Addenbrooke’s Hospital Cambridge UK