What is Emend used for?

Preventing nausea and vomiting caused by chemotherapy for cancer.

Aprepitant is used to prevent acute and delayed sickness that can be caused by chemotherapy, in particular by a medicine called cisplatin, cyclophosphamide, doxorubicin or epirubicin. It is given in combination with a steroid, eg dexamethasone, and a 5HT3 antagonist, eg ondansetron, as part of a three day regimen around each cycle of chemotherapy. These medicines all work in a different way to prevent sickness. Emend makes chemotherapy more tolerable for the patient.

The medicine can only be obtained with a prescription.

How does Emend work?

Vomiting is controlled by an area of the brain called the vomiting centre. The vomiting centre is responsible for causing feelings of sickness (nausea) and for the vomiting reflex. It is activated when it receives nerve messages from another area of the brain called the chemoreceptor trigger zone (CTZ) and when it receives nerve messages from the gut. A protein called substance P is involved in transmitting nerve messages to the vomiting centre. Substance P acts on neurokinin-1 receptors that are found in the vomiting centre in the brain. Chemotherapy causes substance P to activate these neurokinin-1 receptors, resulting in feelings of sickness. Aprepitant works by blocking the neurokinin-1 receptors in the brain. This stops substance P from acting on them and so prevents nausea and vomiting.

How do I take Emend capsules?

• In chemotherapy, the usual dose of Emend in adults and children from 12 years of age is one 125 mg capsule by mouth one hour before the start of chemotherapy. After chemotherapy, one 80 mg capsule is taken each day for the next two days. It must be given with other medicines that also prevent nausea and vomiting, including a corticosteroid (such as dexamethasone) and a ‘5-HT₃ antagonist’ (such as ondansetron).
• Emend 165 mg is given to adults only once, one hour before the start of chemotherapy. It is only given on the first day of the chemotherapy and is followed by treatment involving a corticosteroid and a 5-HT₃ antagonist.
• In children between 6 months and 12 years of age, Emend oral suspension is given together with a 5-HT₃ antagonist. The dose of Emend oral suspension to be given depends on the patient’s bodyweight. Emend oral suspension is given one hour before the start of chemotherapy, and for the next 2 days.
• In PONV, the usual dose is one 40 mg capsule given to adults within the three hours before the patient is anaesthetised (‘put to sleep’).
• Emend capsules should be swallowed whole with a drink. They can be taken either with or without food.

Important information about Emend

This medicine could make hormonal contraceptives, eg the pill, mini-pill or patch, less effective at preventing pregnancy. If you are using hormonal contraceptives, you should use an extra back-up method of contraception, eg condoms, to prevent pregnancy, both during treatment with this medicine and for two months after the last dose. Alternatively, your doctor may suggest that you use a different non-hormonal method of contraception instead. Ask your doctor or pharmacist for further advice.

Emend should be used with caution by people with moderate to severely decreased liver function.

Emend should not be used by

• Children and adolescents under 18 years of age
• People with rare inherited metabolic disorders called acute porphyrias.
• People with rare hereditary problems of fructose intolerance, glucose-galactose malabsorption or sucrase-isomaltase insufficiency as Emend capsules contain sucrose

Do not take Emend with medicines containing pimozide (used to treat psychiatric illnesses), terfenadine and astemizole (used for hay fever and other allergic conditions), cisapride (used for treating digestive problems). Tell the doctor if you or the child is taking these medicines since the treatment must be modified before you or the child start taking EMEND.

This medicine should not be used if you are allergic to any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy.

If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.

Common side effects of Emend (affect between 1 in 10 and 1 in 100 people)

• Decreased appetite.
• Headache.
• Hiccups.
• Constipation.
• Indigestion.
• Fatigue.
• Increased amount of liver enzymes in your blood.

Uncommon side effects of Emend (affect between 1 in 100 and 1 in 1000 people)

• High temperature associated with a drop in levels of white blood cells in the blood (febrile neutropenia).
• Drop in numbers of red blood cells in the blood (anaemia).
• Anxiety.
• Dizziness.
• Sleepiness.
• Palpitations.
• Hot flushes.
• Rash.
• Acne.
• Difficulty or pain passing urine.
• Disturbances of the gut, such as dry mouth, heartburn, abdominal pain, flatulence (wind).
• Feeling weak or generally unwell.

Pregnancy and breastfeeding

• The safety of this medicine for use during pregnancy has not been studied. It should not be used during pregnancy unless considered essential by your doctor. Seek further medical advice from your doctor.
• It is not known if this medicine pases into breast milk. Women who need this medicine should not breastfeed during treatment. Seek further medical advice from your doctor.

Driving and using machines

It should be taken into account that some people feel dizzy and sleepy after taking EMEND. If you or the child feels dizzy or sleepy, avoid driving, riding a bicycle or using machines or tools after taking this medicine

EMEND capsules contain sucrose. If you or the child have been told by your doctor that you or the child have an intolerance to some sugars, contact the doctor before taking this medicine.

If you take more EMEND than you should contact your doctor immediately.

If you forget to take EMEND contact your doctor for advice.

How can Emend affect other medicines?

It is important to tell your doctor or pharmacist what medicines you are already taking, including those bought without a prescription and herbal medicines, before you start treatment with this medicine. Similarly, check with your doctor or pharmacist before taking any new medicines while taking this one, to make sure that the combination is safe.

1)          This medicine should not be taken in combination with the following medicines, as it could increase the amount of these medicines in the blood, potentially causing serious side effects: astemizole, cisapride, pimozide and terfenadine.

2)          Aprepitant may also increase the blood levels of various other medicines, including the following: alfentanil, avanafil, benzodiazepines, bosutinib, ciclosporin, dapoxetine, dexamethasone, dihydroergotamine, diltiazem (this may also increase levels of aprepitant), docetaxel, ergotamine, etoposide, everolimus, fentanyl, ibrutinib, ifosfamide, irinotecan, methylprednisolone, methysergide, paclitaxel, quinidine, sirolimus, tacrolimus and vinorelbine.

If you are having treatment with any of these medicines, you should let your doctor know if you get any new or increased side effects after you start taking this medicine. Your doctor may need to adjust your doses.

3)         Aprepitant may decrease the blood levels of the following medicines, which could make them less effective: phenytoin and tolbutamide.

4)         Aprepitant may decrease the anti-blood-clotting effect of the anticoagulant medicine warfarin. If you regularly take warfarin your blood clotting time (INR) should be monitored closely, both while you are taking this medicine and for two weeks following each three day course.

5)         Aprepitant may reduce the effectiveness of hormonal contraceptives, eg the pill, mini-pill or patch. If you are using hormonal contraceptives, you should use an extra back-up method of contraception, eg condoms, to prevent pregnancy, both during treatment with this medicine and for two months after the last dose. Alternatively, your doctor may suggest that you use a different non-hormonal method of contraception instead.

6)         The following medicines are not recommended while you are having treatment with this medicine, as they could decrease the amount of aprepitant in your blood and make it less effective: carbamazepine, phenobarbital, phenytoin, rifampicin, the herbal remedy St John's wort (Hypericum perforatum).

7)         The following medicines should be used with caution while you are having treatment with this medicine, as they could increase the amount of aprepitant in your blood and so increase the risk of its side effects: clarithromycin, itraconazole, ketoconazole, posaconazole, ritonavir, telithromycin, voriconazole.

References:

https://www.netdoctor.co.uk/medicines/cancer-drugs/a7724/emend-aprepitant/https://www.ema.europa.eu/en/medicines/human/EPAR/emend

https://www.medicines.org.uk/emc/product/8228/smpc

https://www.medicines.org.uk/emc/files/pil.8227.pdf

https://www.rxlist.com/emend-side-effects-drug-center.htm