alimemazine

Action and Spectrum

Actions and spectrum: 

alimemazine is an antihistamine with sedative properties. It belongs to the class of first-generation antihistamines. It primarily works by blocking the action of histamine, a chemical in the body that’s involved in allergy symptoms.

As a result, it can relieve symptoms such as sneezing, runny nose, itching, and watery eyes. Its sedative properties makes it useful for treating conditions like allergies, hay fever, and insomnia. 

The spectrum of alimemazine’s action is mainly related to its antihistaminic and sedative effects, making it effective for managing allergic reactions and promoting sleep. 

Drug Interaction

Adverse Reaction

Frequency not defined 

Nasal stuffiness 

insomnia 

convulsion 

hypotension 

AV block 

ECG changes 

akathisia 

tremor 

akinesia 

skin rashes 

ocular changes 

Hyperprolactinaemia 

paradoxical excitement 

agranulocytosis 

dry mouth 

agitation 

jaundice 

Pallor 

ventricular tachycardia 

mild leucopenia 

acute dystonia 

Parkinsonism 

rigidity 

tardive dyskinesia 

Photosensitivity 

paradoxical excitement 

Black Box Warning

Black Box Warning: 

There was no specific black box warning associated with alimemazine. 

Contraindication / Caution

Contraindication/Caution: 

Contraindication: 

• Hypersensitivity: alimemazine should not be used in individuals who have a known hypersensitivity or allergy to the drug or its components. 
• Respiratory Depression: It is contraindicated in individuals with severe respiratory depression or conditions associated with significant airway obstruction, such as asthma attacks, chronic obstructive pulmonary disease (COPD), or sleep apnea. 
• Acute Alcohol Intoxication: Combining alimemazine with acute alcohol intoxication can potentiate central nervous system depression and is contraindicated. 
• Comatose State: alimemazine should not be administered to individuals in a comatose state, as it can further depress the central nervous system. 
• Pediatric Patients: alimemazine should be used with caution or avoided in young children, especially those under two years of age, due to the risk of severe respiratory depression.

Caution: 

• Central Nervous System Depression: alimemazine has a sedative effect and can cause central nervous system depression. Caution should be exercised when using alimemazine in individuals who are already experiencing central nervous system depression, such as from the use of other sedative medications. 
• Alcohol: Patients should avoid or limit alcohol consumption while taking alimemazine. The combination of alcohol and alimemazine can potentiate sedation and central nervous system depression. 
• Psychiatric Conditions: Patients with certain psychiatric conditions, especially those prone to depressive episodes, should use alimemazine with caution, as it may affect mood and exacerbate depression. 
• Seizure Disorders: alimemazine may lower the seizure threshold. Patients with a history of seizures or those at risk of seizures should use alimemazine cautiously, and its use should be monitored by a healthcare provider. 
• Renal or Hepatic Impairment: Patients with impaired renal or hepatic function may require dosage adjustments, as alimemazine’s pharmacokinetics may be affected in these individuals.

Comorbidities: 

• Cardiovascular Disease: alimemazine can cause changes in heart rate and blood pressure. Patients with pre-existing cardiovascular conditions, such as arrhythmias, congestive heart failure, or hypertension, should be monitored closely when using alimemazine. 
• Kidney Disease: Kidney function can affect the clearance of drugs from the body. Patients with kidney disease may require dosage modifications when using alimemazine. 
• Mental Health Conditions: alimemazine has central nervous system depressant effects and may affect mood. Patients with psychiatric comorbidities, such as depression, bipolar disorder, or anxiety, should use alimemazine with caution, as it may exacerbate these conditions. 
• Alcohol or Substance Abuse: Patients with a history of alcohol or substance abuse should be cautious with alimemazine, as it can potentiate the sedative effects of these substances. 
• Glaucoma: alimemazine may worsen the symptoms of narrow-angle glaucoma. Patients with this eye condition should use alimemazine with caution. 

Pregnancy / Lactation

Pregnancy consideration: pregnancy category: not assigned 

Lactation: excreted into human milk: unknown  

Pregnancy category: 

• Category A: well-controlled and Satisfactory studies show no risk to the fetus in the first or later trimester. 
• Category B: there was no evidence of risk to the fetus in animal studies, and there were not enough studies on pregnant women. 
• Category C: there was evidence of risk of adverse effects in animal reproduction studies, and no adequate evidence in human studies must take care of potential risks in pregnant women.   
• Category D: adequate data with sufficient evidence of human fetal risk from various platforms, but despite the potential risk, and used only in emergency cases for potential benefits. 
• Category X: Drugs listed in this category outweigh the risks over benefits. Hence these categories of drugs need to be avoided by pregnant women. 
• Category N: There is no data available for the drug under this category. 

Pharmacology

Pharmacology: 

alimemazine, a medication with antihistamine and sedative properties, exerts its pharmacological effects primarily by blocking histamine H1 receptors in the central nervous system and peripheral tissues. By inhibiting histamine’s action, it mitigates allergic responses and helps manage symptoms like itching, sneezing, and runny nose.

Furthermore, alimemazine’s sedative effects result from its influence on various neurotransmitters in the brain, including gamma-aminobutyric acid (GABA) and serotonin receptors. These effects contribute to its use as a sedative-hypnotic agent, often prescribed for its calming and sleep-inducing properties.  

Pharmacodynamics: 

• Histamine H1 Receptor Antagonism: alimemazine is an antagonist of histamine H1 receptors. By blocking these receptors, it prevents the action of histamine, a neurotransmitter involved in allergic reactions. This receptor antagonism helps alleviate symptoms of allergies, such as itching, sneezing, and runny nose. 
• Sedative-Hypnotic Effects: alimemazine exhibits sedative and hypnotic properties. These effects are primarily mediated through its influence on neurotransmitters like gamma-aminobutyric acid (GABA) and serotonin receptors in the central nervous system. By enhancing inhibitory signals and reducing neuronal activity, alimemazine induces a calming and sleep-inducing effect. 
• Anticholinergic Activity: alimemazine has anticholinergic properties, meaning it blocks the action of acetylcholine, another neurotransmitter. This effect can lead to side effects like dry mouth, blurred vision, and constipation. 
• Alpha-Adrenergic Receptor Blockade: Some sedative effects of alimemazine may result from its blockade of alpha-adrenergic receptors. By reducing the activity of these receptors, it contributes to its sedative and calming properties. 
• Dopaminergic Receptor Blockade: alimemazine may also interact with dopaminergic receptors, which could impact mood and alertness.

Pharmacokinetics: 

Absorption 

alimemazine is well-absorbed after oral administration. Its absorption from gastrointestinal tract can be influenced by factors like food, which may delay the onset of action when taken with a meal. 

Distribution 

alimemazine is distributed throughout the body, including the central nervous system, due to its lipophilic nature. It crosses blood-brain barrier and the placenta, which may affect its sedative and hypnotic properties. alimemazine is also known to be highly protein-bound in the bloodstream, primarily to albumin. 

Metabolism 

alimemazine undergoes hepatic metabolism, primarily in the liver. It is metabolized through a process called N-dealkylation, leading to the formation of several metabolites. The enzymes responsible for this metabolic pathway include cytochrome P450 2D6 (CYP2D6) and cytochrome P450 2B6 (CYP2B6). 

Elimination and excretion 

The metabolites of alimemazine, as well as a portion of the unchanged drug, are excreted primarily in the urine. The excretion of these metabolites and the elimination half-life of alimemazine may vary among individuals but is typically within a few hours. 

Adminstartion

Administration: 

Oral Tablets: 

• alimemazine tablets are meant to be taken by mouth. 
• Usually, tablets are swallowed with a full glass of water, with or without food. 

Oral Syrup: 

• If you are using the syrup form of alimemazine, measure the dose using a special dose-measuring spoon or a medication cup.  
• Shake the bottle well before use, as some settling may occur. 

Patient Information Leaflet

Patient information leaflet 

Generic Name: alimemazine 

Pronounced: (uh-LIM-em-a-zeen) 

Why do we use alimemazine? 

alimemazine is commonly used to relieve the symptoms of various allergic conditions, such as hay fever, allergic rhinitis, and allergic conjunctivitis. It can help alleviate symptoms like runny nose, sneezing, watery eyes, and itching of the skin. alimemazine has sedative properties and may be used to induce sleep or reduce anxiety in some situations.

It is sometimes prescribed as a short-term sedative or for managing anxiety disorders. alimemazine can be used to manage nausea and vomiting, particularly in cases of motion sickness.