BRAND NAMES
 MECHANISM OF ACTION
Vomiting is a complex process coordinated centrally by the emetic center which consists of several brainstem nuclei (area postrema, nucleus tractus solitarius, dorsal motor nucleus of the vagus) that receive and integrate sensory stimuli from central and peripheral sources and chemical stimuli from the circulation and the cerebro-spinal fluid.
Maropitant is a neurokinin 1 (NK1) receptor antagonist which acts by inhibiting the binding of substance P, a neuropeptide of the tachykinin family. Substance P is found in significant concentrations in the nuclei comprising the emetic center and is considered the key neurotransmitter involved in emesis.1 By inhibiting the binding of substance P within the emetic center, maropitant provides broad-spectrum effectiveness against neural (central) and humoral (peripheral) causes of vomiting.
Tablets and injection:
- Prevention of acute vomiting and the prevention of vomiting due to motion sickness in dogs.
- Prevention of nausea induced by chemotherapy in dogs
- Prevention of vomiting and the reduction of nausea, except that induced by motion sickness in cats
- For the treatment of vomiting, in combination with other supportive measures in cats.
- For the Prevention of Nausea induced by Chemotherapy and Treatment and Prevention of Vomiting (except Motion Sickness), (only for dogs 8 weeks of age or older): Administer Maropitant Tablets orally at a minimum dose of 2 mg/kg (0.9 mg/lb) body weight once daily for up to 5 consecutive days
- For Prevention of Vomiting induced by Motion Sickness, (only for dogs 16 weeks of age or older) : Administer Maropitant Tablets orally at a minimum dose of 8 mg/kg (3.6 mg/lb) body weight once daily for up to 2 consecutive days. Dogs should be fasted 1 hour prior to administration of Maropitant Tablets. Administer Maropitant Tablets 2 hours prior to travel.
- Prevention and treatment of acute vomiting in dogs. Administer Maropitant Injectable Solution subcutaneously at 1.0 mg/kg (0.45 mg/lb) equal to 1.0 mL/10 kg (1.0 mL/22 lb) of body weight once daily for up to 5 consecutive days. To prevent vomiting, Maropitant solution for injection should be administered more than 1 hour in advance. The effect duration is approximately 24 h and therefore treatment can be given the night before administration of an agent that may cause emesis e.g. chemotherapy.
- Maropitant solution for injection should be injected subcutaneously, once daily, at a dose of 1 mg/kg bodyweight (1 ml/10 kg bodyweight) for up to 5 consecutive days. To prevent vomiting, Maropitant solution for injection should be administered more than 1 hour in advance. The effect duration is approximately 24 h.
where the frequency of vomiting is high, orally administered Maropitant may not be absorbed before the next vomiting event occurs. It is therefore recommended to initiate the treatment of emesis with Maropitant Solution for Injection.
Maropitant should be used with caution in animals suffering from or with predisposition for cardiac diseases as maropitant has affinity to Ca- and K-ion channels. Increases of approximately 10% in the QT interval of the ECG were observed in a study on healthy beagle dogs administered 8 mg/kg orally; however, such an increase is unlikely to be of clinical significance.
Maropitant should not be used concomitantly with Ca-channel antagonists as maropitant has affinity to Ca-channels.
Maropitant is highly bound to plasma proteins and may compete with other highly bound drugs.
 PREGNANCY AND LACTATION
Use only according to the benefit/risk assessment by the responsible veterinarian, because conclusive reproductive toxicity studies have not been conducted in any animal species.
 SIDE EFFECTS
A common side effect of the tablets when used at a high dose of 8 mg/kg in dogs (for motion sickness) was vomiting before the car journey started. Since this was mainly observed in dogs with an empty stomach, it is recommended to feed a light meal or snack a while before the tablets are given. Other reported side effects were decreased activity levels and tiredness.
 RELATED LINKS
|5-HT3 receptor antagonists||Dolasetron • Granisetron • Ondansetron • Palonosetron • Tropisetron|
|Dopamine antagonists||Alizapride • Bromopride • Clebopride • Domperidone • Metoclopramide • Prochlorperazine • Thiethylperazine|
|H1 antagonists||Dimenhydrinate • Meclizine|
|NK1 receptor antagonists||Aprepitant • Fosaprepitant • Maropitant|
|Motion sickness||Cinnarizine • Dimenhydrinate • Meclizine • Meclizine/Pyridoxine • Scopolamine (Patch)|
|Pregnancy||Meclizine/Pyridoxine • Ondansetron|