Antiemetic/antivertigo agents

Antiemetic/antivertigo agents

Vomiting is controlled by the vomiting center in the medulla. Vomiting center is activated by either one of four trigger zones: chemoreceptor trigger zone, vestibular nuclei, cerebral cortex and gastrointestinal tract. Vomiting center is controlled by serotonin (5-HT3), muscarinic and histamine (H1) receptors.

Chemoreceptor trigger zone is sensitive to chemical stimuli, such as opioids and cytotoxic drugs. It is under the control of dopamine, serotonin (5-HT3) and opioid receptors.

Vestibular nuclei is controlled by muscarinic and histamine (H1) receptors. This is activated in vertigo or motion sickness.

Cerebral cortex activates vomiting from smell, thought and so on. Gastrointestinal tract has serotonin (5-HT3) receptors, which are affected by chemotherapeutic drugs.

Different classes of drugs work on different receptors and act as antiemetics and antivertigo agents.

5HT3 receptor antagonists

5-HT3 receptor antagonists (also called serotonin receptor antagonists or serotonin blockers) are a class of medicines that are used for the prevention and treatment of nausea and vomiting, particularly that caused by chemotherapy, radiation therapy, or postoperatively. 5-HT3 is an abbreviation for serotonin that may also be written as 5-hydroxytryptamine.

Cells lining the gastrointestinal tract release serotonin when damaged by chemotherapy and radiation therapy. This serotonin binds to serotonin receptors on nerves that transmit impulses to the vomiting center within the brain, which in turn stimulates other nerves involved in the vomit reflex. 5-HT3 receptor antagonists prevent serotonin from binding to 5-HT3 receptors in the small intestine thereby reducing the likelihood of nausea and vomiting. The way 5-HT3 receptor antagonists work to prevent postoperative nausea and vomiting is less well understood.

The first generation 5-HT3 receptor antagonists include dolasetron, granisetron, and ondansetron. Despite variations in their chemical structures and absorption rates, they all work in the same way and are well tolerated. The oral formulations are just as effective at preventing nausea and vomiting as the intravenous forms.

Palonosetron is a second-generation serotonin blocker. It has a greater affinity for serotonin receptors than first generation agents, which increases its duration of effect. Palonosetron is also thought to have an effect on 5-HT3 receptors in the vomiting center and chemoreceptor trigger zone as well, not just the small intestine. It is approved for both acute and delayed chemotherapy-induced nausea and vomiting.

Palonosetron:

• It is used to treat or prevent upset stomach and throwing up.

 Dolasetron Injection:

• It is used to treat or prevent upset stomach and throwing up.

 

Granisetron Extended-Release Injection:

It is used to prevent upset stomach and throwing up.It may be given to you for other reasons. Talk with the doctor. What are some things I need to know or do while I take Granisetron Extended-Release Injection?Tell all of your health care providers that you take this medicine. This includes your doctors, nurses, pharmacists, and dentists.It is common to have injection site reactions with granisetron extended-release injection. Some injection site reactions may happen up to 2 weeks or more after getting this medicine. Some of these reactions may be very bad and need treatment. Talk with your doctor.Allergic reactions may happen up to 7 days or more after getting granisetron extended-release injection. Talk with your doctor.Tell your doctor if you are pregnant or plan on getting pregnant. You will need to talk about the benefits and risks of using this medicine while you are pregnant.Tell your doctor if you are breast-feeding. You will need to talk about any risks to your baby.

         ondansetron:

Ondansetron blocks the actions of chemicals in the body that can trigger nausea and vomiting.
Ondansetron is used to prevent nausea and vomiting that may be caused by surgery, cancer chemotherapy, or radiation treatment.

Anticholinergic antiemetics

Anticholinergic antiemetics are agents that block muscarinic receptors and inhibit cholinergic transmission from the vestibular nuclei to the vomiting center.

Anticholinergic antiemetics are mainly used to prevent or treat motion sickness.

Diphenhydramine

Diphenhydramine is an antihistamine that reduces the effects of natural chemical histamine in the body. Histamine can produce symptoms of sneezing, itching, watery eyes, and runny nose.
Diphenhydramine is used to treat sneezing, runny nose, watery eyes, hives, skin rash, itching, and other cold or allergy symptoms.
Diphenhydramine is also used to treat motion sickness, to induce sleep, and to treat certain symptoms of Parkinson's disease.

 When taking diphenhydramine, use caution driving, operating machinery, or performing other hazardous activities. Diphenhydramine may cause dizziness or drowsiness. If you experience dizziness or drowsiness, avoid these activities.
Use alcohol cautiously. Alcohol may increase drowsiness and dizziness while taking diphenhydramine.
Do not give this medication to a child younger than 2 years old. Always ask a doctor before giving a cough or cold medicine to a child. Death can occur from the misuse of cough and cold medicines in very young children.

Usual Adult Dose for Extrapyramidal Reaction
Oral: 25 to 50 mg orally 3 to 4 times a day
Parenteral: 10 to 50 mg deep IM or IV as needed, and may increase to 100 mg if required
-Maximum dose: 400 mg/day
Comment:
-IV injection rates should not exceed 25 mg/min.
Uses:
-Parkinsonism of the elderly who are unable to tolerate more potent agents
-Mild cases of parkinsonism in other age groups
-Other cases of parkinsonism in combination with centrally acting anticholinergic agents

Usual Adult Dose for Insomnia
Diphenhydramine Citrate: 76 mg orally once a day at bedtime
Diphenhydramine Hydrochloride: 50 mg orally once a day at bedtime
Comment:
-Patients should contact their healthcare provider if symptoms of insomnia persist for more than 2 weeks while receiving treatment.
Uses:
-As a nighttime sleep aid
-To reduce difficulty falling asleep
-Relief of occasional sleeplessness

Usual Adult Dose for Motion Sickness
Oral:
-Prescription formulations: 25 to 50 mg orally 3 to 4 times a day, with the first dose given 30 minutes before exposure to motion and repeated before meals and upon retiring throughout the duration of the journey.
Parenteral: 10 to 50 mg deep IM or IV as needed, and may increase to 100 mg if required
-Maximum dose: 400 mg/day
Comment:
-IV injection rates should not exceed 25 mg/min.
Use:
-Active and prophylactic treatment of motion sickness

Usual Adult Dose for Allergic Rhinitis
Oral:
Diphenhydramine Citrate: 38 to 76 mg orally every 4 to 6 hours as needed
-Maximum dose: 456 mg/day
Diphenhydramine Hydrochloride: 25 to 50 mg orally every 4 to 6 hours as needed
-Maximum dose: 300 mg/day
Parenteral: 10 to 50 mg deep IM or IV as needed, and may increase to 100 mg if required
-Maximum dose: 400 mg/day
Comment:
-IV injection rates should not exceed 25 mg/min.
Uses:
-Allergic conjunctivitis due to foods
-Mild, uncomplicated allergic skin manifestations of urticaria and angioedema
-Amelioration of allergic reactions to blood or plasma
-Dermatographism
-Therapy for anaphylactic reactions adjunctive to epinephrine and other standard measures after acute manifestations have been controlled
-Temporary relief of runny nose, itchy, watery eyes, sneezing, and itching of the nose/throat due to hay fever or other upper respiratory allergies
-Temporarily relieves runny nose and sneezing due to the common cold

         Cyclizine:

It is used to help motion sickness.It is used to treat upset stomach and throwing up.It may be given to you for other reasons. Talk with the doctor.

Phenothiazine antiemetics

Phenothiazine antiemetics are a type of medicine that may be used to relieve nausea and vomiting. They work by inhibiting dopamine, muscarinic and histamine (H1) receptors generally in the vomiting center and chemoreceptor trigger zone.

Phenothiazine antiemetics are usually reserved for severe cases of nausea and vomiting that occur as a result of chemotherapy or radiotherapy. Drowsiness and extrapyramidal side effects (unusual movement disorders) are common side effects. Some phenothiazine antiemetics are also used in the treatment of psychosis and schizophrenia.

Promethazine

Promethazine is in a group of drugs called phenothiazines (FEEN-oh-THYE-a-zeens). It works by changing the actions of chemicals in your brain. Promethazine also acts as an antihistamine. It blocks the effects of the naturally occurring chemical histamine in your body.
Promethazine is used to treat allergy symptoms such as itching, runny nose, sneezing, itchy or watery eyes, hives, and itchy skin rashes. It also prevents motion sickness, and treats nausea and vomiting or pain after surgery. It is also used as a sedative or sleep aid.
Promethazine is not for use in treating symptoms of asthma, pneumonia, or other lower respiratory tract infections.

 Stop using promethazine and call your doctor at once if you have twitching or uncontrollable movements of your eyes, lips, tongue, face, arms, or legs. These could be early signs of dangerous side effects. Promethazine should not be given to a child younger than 2 years old. Promethazine can cause severe breathing problems or death in a child in very young children. Carefully follow your doctor's instructions when giving this medicine to a child of any age.

 Rare - Symptoms of neuroleptic malignant syndrome; two or more occur together; most of these effects do not require emergency medical attention if they occur alone

• Convulsions (seizures)
• difficult or unusually fast breathing
• fast heartbeat or irregular pulse
• high fever
• high or low (irregular) blood pressure
• increased sweating
• loss of bladder control
• severe muscle stiffness
• unusually pale skin
• unusual tiredness or weakness

Usual Adult Dose for Allergic Reaction
Oral or Rectal: 6.25 to 12.5 mg orally or rectally before meals and at bedtime, if necessary, OR 25 mg orally or rectally once a day at bedtime
Parenteral: 25 mg IM or IV once, and may be repeated within 2 hours if necessary
Comments:
-Once treatment begins, the dose should be reduced to the smallest effective amount needed to control symptoms.
-Minor transfusion and/or amelioration of allergic reactions may be controlled with 25 mg doses.
Uses:
-Allergic conjunctivitis due to inhalant allergens and foods
-Amelioration of allergic reactions to blood or plasma
-Dermographism
-In anaphylaxis as an adjunct to epinephrine and other standard measures after the acute symptoms have been controlled
-Mild, uncomplicated allergic skin manifestations of urticaria and angioedema
-Other uncomplicated allergic condition of the immediate type when oral therapy is impossible or contraindicated
-Perennial and seasonal allergic rhinitis
-Vasomotor rhinitis

Usual Adult Dose for Allergic Rhinitis
Oral or Rectal: 6.25 to 12.5 mg orally or rectally before meals and at bedtime, if necessary, OR 25 mg orally or rectally once a day at bedtime
Parenteral: 25 mg IM or IV once, and may be repeated within 2 hours if necessary
Comments:
-Once treatment begins, the dose should be reduced to the smallest effective amount needed to control symptoms.
-Minor transfusion and/or amelioration of allergic reactions may be controlled with 25 mg doses.
Uses:
-Allergic conjunctivitis due to inhalant allergens and foods
-Amelioration of allergic reactions to blood or plasma
-Dermographism
-In anaphylaxis as an adjunct to epinephrine and other standard measures after the acute symptoms have been controlled
-Mild, uncomplicated allergic skin manifestations of urticaria and angioedema
-Other uncomplicated allergic condition of the immediate type when oral therapy is impossible or contraindicated
-Perennial and seasonal allergic rhinitis
-Vasomotor rhinitis

Usual Adult Dose for Anaphylaxis
Oral or Rectal: 6.25 to 12.5 mg orally or rectally before meals and at bedtime, if necessary, OR 25 mg orally or rectally once a day at bedtime
Parenteral: 25 mg IM or IV once, and may be repeated within 2 hours if necessary
Comments:
-Once treatment begins, the dose should be reduced to the smallest effective amount needed to control symptoms.
-Minor transfusion and/or amelioration of allergic reactions may be controlled with 25 mg doses.
Uses:
-Allergic conjunctivitis due to inhalant allergens and foods
-Amelioration of allergic reactions to blood or plasma
-Dermographism
-In anaphylaxis as an adjunct to epinephrine and other standard measures after the acute symptoms have been controlled
-Mild, uncomplicated allergic skin manifestations of urticaria and angioedema
-Other uncomplicated allergic condition of the immediate type when oral therapy is impossible or contraindicated
-Perennial and seasonal allergic rhinitis
-Vasomotor rhinitis

Usual Adult Dose for Motion Sickness
Treatment:
-Oral and Rectal: 25 mg orally, or rectally once, then 12.5 to 25 mg every 4 to 6 hours as needed
-Parenteral: 12.5 to 25 mg IM or IV every 4 hours as needed
Prophylaxis:
-Initial day: 25 mg orally or rectally 30 to 60 minutes before traveling, then 8 to 12 hours as needed
-Succeeding days of travel: 25 mg orally or rectally upon rising, with the dose repeated before the evening meal
Comment:
-Oral formulations are preferred; however, rectal or parenteral formulations may be given if oral formulations are not tolerated.
Use:
-Active and prophylactic treatment of motion sickness

Usual Adult Dose for Nausea/Vomiting
Treatment: 12.5 to 25 mg IM, IV, orally, or rectally every 4 hours as needed
Prophylaxis:
-Oral and Rectal: 25 mg orally every 4 to 6 hours as needed
Comments:
-Parenteral or rectal formulations may be used when patients cannot tolerate oral formulations.
-Prophylactic doses may be used to prevent nausea and vomiting during surgery and the postoperative period.
Uses:
-Prevention and control of nausea and vomiting associated with certain types of anesthesia and surgery
-Antiemetic therapy in postoperative patients

Usual Pediatric Dose for Allergic Reaction
2 years and older:
Oral or Rectal: 6.25 to 12.5 mg orally or rectally before meals and at bedtime, as necessary OR 25 mg orally or rectally once a day at bedtime
Parenteral: 12.5 mg IM or IV once, and may be repeated within 2 hours if necessary
Comments:
-Once treatment begins, the dose should be reduced to the smallest effective amount needed to control symptoms.
-Minor transfusion and/or amelioration of allergic reactions may be controlled with 12.5 mg doses.
Uses:
-Perennial and seasonal allergic rhinitis
-Vasomotor rhinitis
-Allergic conjunctivitis due to inhalant allergens and foods
-Mild, uncomplicated allergic skin manifestations of urticaria and angioedema
-Amelioration of allergic reactions to blood or plasma
-Dermographism
-Adjunctive therapy to epinephrine and other standard measures for anaphylactic reactions, after acute manifestations have been controlled

Usual Pediatric Dose for Motion Sickness
2 years and older:
Treatment:
-Parenteral: 6.25 to 12.5 mg IM or IV every 4 hours a day
Treatment and prevention:
-Oral and Rectal: 12.5 to 25 mg orally or rectally 2 times a day
Comments:
-The initial dose should be given 30 to 60 minutes before anticipated travel, and may be repeated in 8 to 12 hours as needed.
-Subsequent doses on succeeding days of travel should be given on rising and again before the evening meal.
Use:
-Active and prophylactic treatment of motion sickness

Prochlorperazine Injection

It is used to treat upset stomach and throwing up.It is used to treat schizophrenia.It may be given to you for other reasons. Talk with the doctor.

 Side effects include:Drowsiness, dizziness, amenorrhea, blurred vision, skin reactions, hypotension.

Usual Adult Dose for Nausea/VomitingSevere Nausea and Vomiting:
Oral:
-Usual dose: 5 to 10 mg orally 3 to 4 times a day
-Maximum dose: 40 mg/day
Parenteral:
IM:
-Usual dosage: 5 to 10 mg IM, repeated every 3 to 4 hours as necessary.
-Maximum dose: 40 mg/day
IV:
-Usual dose: 2.5 to 10 mg slow IV injection or infusion at a rate not exceeding 5 mg/min
-Maximum dose: 10 mg (single dose); 40 mg/day
Rectal:
-Usual dose: 25 mg rectally 2 times a day
Adult Surgery (Severe Nausea and Vomiting):
Parenteral:
IM:
-Usual dose: 5 to 10 mg IM 1 to 2 hours before anesthesia OR to control acute symptoms during/after surgery, repeated once (in 30 minutes) if necessary
-Maximum dose: 40 mg/day
IV:
-Usual dose: 5 to 10 mg slow IV injection or infusion (at a rate not exceeding 5 mg/min) 15 to 30 minutes before anesthesia OR to control acute symptoms during/after surgery, repeated once if necessary
-Maximum dose: 10 mg (single dose)
Comments:
-Resistant cases may require oral doses exceeding 40 mg/day.
-Patients receiving parenteral formulations may be more likely to experience hypotension.
-This drug may be given as an undiluted or diluted IV solution; however, bolus IV injections should be avoided.
Use: Control of severe nausea and vomiting

Usual Adult Dose for AnxietyOral:
-Usual dose: 5 mg orally 3 to 4 times a day
-Maximum dose: 20 mg/day
-Duration of therapy: Up to 12 weeks
Use: Short-term treatment of generalized non-psychotic anxiety

Usual Adult Dose for Psychosis
Mild psychotic disorders:
-Usual dose: 5 to 10 mg orally 3 to 4 times a day
Moderate to severe psychotic disorders:
Oral:
-Initial dose: 10 mg orally 3 to 4 times a day, increasing the dose in small increments every 2 to 3 days until symptoms are controlled or side effects become bothersome
-Maintenance dose: 50 to 75 mg/day for some patients; 100 to 150 mg/day for patients with more severe disturbances
Parenteral:
-Initial dose: 10 to 20 mg IM, repeated every 2 to 4 hours (or every hour in resistant cases), if necessary
-Prolonged therapy: 10 to 20 mg IM every 4 to 6 hours

Usual Pediatric Dose for Nausea/Vomiting
Less than 2 years or less than 9 kg: Use is contraindicated
2 years and older:
Oral:
9 to 13 kg: 2.5 mg orally 1 to 2 times a day; maximum dose is 7.5 mg/day
13 to 18 kg: 2.5 mg orally 2 to 3 times a day; maximum dose is 10 mg/day
18 to 39 kg: 2.5 mg orally 3 times a day OR 5 mg orally 2 times a day; maximum dose is 15 mg/day
Parenteral:
-Usual dose: 0.132 mg/kg IM once
Comments:
-At moderate doses, pediatric patients may be more prone to extrapyramidal reactions. Patients should receive the lowest effective dose.
-Continued oral treatment after day 1, and parenteral treatment after the first dose is usually not necessary.
Use: Control of severe nausea and vomiting

NK1 receptor antagonists

Neurokinin-1 (NK1) receptor antagonists are used for prevention of acute and delayed nausea and vomiting. The NK1 receptor antagonist competitively binds to the NK1 receptor, which blocks the binding of substance P and prevents the emetic signal being transmitted. NK1 receptor antagonists can be used in conjunction with 5-HT3-receptor antagonists and corticosteroids to augment their antiemetic activity.

Rolapitant:

It is used to prevent upset stomach and throwing up from chemo.
It may be given to you for other reasons. Talk with the doctor.

Aprepitant Capsules:
It is used to prevent upset stomach and throwing up from chemo.
It is used to prevent upset stomach and throwing up from surgery.

It may be given to you for other reasons. Talk with the doctor.