LEVOZIN 5

Indications

• Seasonal allergic rhinitis
• Chronic idiopathic urticaria

Dosage

Children: For children aged 6 to 11 years, the dose is 30 mg twice daily. For children aged 12 to 17 years, the dose is 120 mg once daily.

Adults: For adults, the recommended dose is 180 mg once daily.

Mechanism of action

Levocetirizine is an active enantiomer of cetirizine and functions as a selective antagonist of the peripheral H1 receptor. By blocking the action of histamine, a key mediator in allergic responses, it reduces symptoms such as sneezing, itching, and runny nose. It also prevents the activation of sensory neurons, thereby mitigating pruritus and swelling associated with allergic reactions.

Pharmacodynamics

Levocetirizine exhibits antihistaminic effects with a rapid onset of action. Its affinity for peripheral H1 receptors allows it to effectively reduce the symptoms of allergic rhinitis and urticaria. While it is termed 'non-sedating', some degree of sedation may still occur in sensitive individuals, although this is generally minimal compared to first-generation antihistamines.

Pharmacokinetics

Levocetirizine is well absorbed after oral administration, with peak plasma concentrations typically reached within 0.9 hours. The drug has a volume of distribution of approximately 0.4 L/kg and is primarily excreted unchanged in urine. It has a half-life of about 8 hours, allowing for once-daily dosing. In patients with renal impairment, dose adjustments may be necessary due to altered drug clearance.

Contra-indications

• Acute porphyrias

Adverse effects

• Asthenia
• Constipation
• Drowsiness
• Dry mouth
• Abdominal pain
• Aggression
• Agitation
• Angioedema
• Appetite increased
• Arthralgia
• Depression
• Diarrhoea
• Dizziness
• Fatigue
• Hallucination
• Hepatitis
• Myalgia
• Nausea
• Oedema
• Palpitations
• Paraesthesia
• Seizure
• Skin reactions
• Sleep disorders
• Suicidal ideation
• Syncope
• Tachycardia
• Taste altered
• Tremor
• Urinary disorders
• Vertigo
• Vision disorders
• Vomiting
• Weight increased

Interactions

• Other antihistamines
• Alcohol (may increase sedation)
• CNS depressants

Precautions

• Caution in renal impairment
• Patients should be advised about potential drowsiness affecting driving and skilled tasks

Pregnancy

Most manufacturers of antihistamines advise avoiding their use during pregnancy; however, there is no evidence of teratogenicity.

Breast-feeding

Most antihistamines are present in breast milk in varying amounts; although not known to be harmful, most manufacturers advise avoiding their use in mothers who are breastfeeding.

Storage

Store in a cool, dry place away from light. Keep out of reach of children.

Formulations

• Oral suspension
• Oral solution
• Tablets

Indications

• Constipation
• Dietary fiber supplementation
• Irritable bowel syndrome
• Diverticular disease
• Weight management

Dosage

Children: Refer to appropriate guidelines for specific dosage; generally taken with adequate fluid intake.

Adults: Refer to appropriate guidelines for specific dosage; generally taken with adequate fluid intake.

Mechanism of action

Cellulose acts primarily as a bulk-forming laxative. It absorbs water in the intestines, which increases stool bulk and stimulates peristalsis, thus facilitating bowel movements. Additionally, cellulose is not digestible by human enzymes, leading to fermentation by gut bacteria, which may enhance gut health and alter gut microbiota composition.

Pharmacodynamics

Cellulose increases stool weight and frequency of bowel movements. It works by retaining water in the intestines, leading to softer stools and improved passage through the gastrointestinal tract. The bulking effect of cellulose can help alleviate constipation and promote overall digestive health. It may also play a role in cholesterol reduction and glycemic control through its effects on digestion and absorption of nutrients.

Pharmacokinetics

Cellulose is not absorbed into the bloodstream due to its indigestible nature. Instead, it passes through the gastrointestinal tract, where it adds bulk to the stool. Its fermentation by colonic bacteria produces short-chain fatty acids, which may have beneficial effects on colon health. The onset of action for cellulose as a laxative can vary but is generally within 24 to 72 hours after ingestion.

Adverse effects

• Bloating
• Flatulence
• Diarrhea
• Abdominal discomfort

Precautions

• Use with caution in patients with a history of gastrointestinal disorders.
• Monitor for potential allergic reactions in sensitive individuals.

Pregnancy

Cellulose is generally considered safe during pregnancy as it is a non-toxic, indigestible fiber.

Breast-feeding

Cellulose is also considered safe during breastfeeding; it is excreted in breast milk in negligible amounts.

Storage

Store in a cool, dry place away from direct sunlight.

Formulations

• Powder
• Capsules
• Tablets
• Granules

Indications

• Constipation
• Bowel preparation for surgical procedures
• Bowel preparation for diagnostic procedures

Dosage

Children: Refer to the BNF for Children for appropriate pediatric dosing.

Adults: Refer to the prescribing information or clinical guidelines for specific adult dosing recommendations.

Mechanism of action

Colorezy acts by osmotic effects in the intestines, drawing water into the bowel lumen. This increases the intraluminal pressure and stimulates peristalsis, leading to a softening of the stool and enhanced bowel movement.

Pharmacodynamics

The pharmacodynamic profile of Colorezy involves the modulation of intestinal fluid balance. By promoting the retention of water in the stool, it reduces stool hardness and increases the frequency of bowel movements. The laxative effect is typically observed within a few hours after administration, depending on the dosage and the individual's gastrointestinal transit time.

Pharmacokinetics

Colorezy is not absorbed systemically and acts locally within the gastrointestinal tract. It exerts its effects within the lumen of the intestines. The onset of action can vary, but generally occurs within 1 to 3 days following administration. The elimination of its effects is primarily through fecal excretion as it is not metabolized by the liver or kidneys.

Pregnancy

The safety of colorezy in pregnancy has not been established. It should be used only if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

It is unknown whether colorezy is excreted in human milk. Caution should be exercised when administering to nursing mothers.

Storage

Store at room temperature, away from moisture and heat. Keep out of reach of children.

Indications

• Used as a disintegrant in tablet and capsule formulations
• Enhancement of drug bioavailability
• Facilitation of rapid disintegration of oral dosage forms

Dosage

Children: Refer to the specific formulation guidelines, as croscarmellose sodium is used in varying concentrations depending on the formulation.

Adults: Refer to the specific formulation guidelines, as croscarmellose sodium is used in varying concentrations depending on the formulation.

Mechanism of action

Croscarmellose sodium acts by swelling and forming a gel-like structure upon contact with water. This swelling leads to the rapid breakdown of the tablet or capsule matrix, facilitating the liberation of active pharmaceutical ingredients. The mechanism involves the hydration of the polymer chains, which disrupts the cohesive forces in the formulation, allowing for quicker disintegration and subsequent absorption.

Pharmacodynamics

As a disintegrant, croscarmellose sodium does not exert pharmacological effects on the body but rather enhances the delivery and effectiveness of other active drugs. Its role is crucial in ensuring that medications dissolve properly, thereby influencing the onset of action, peak plasma concentrations, and overall therapeutic efficacy of the administered drugs.

Pharmacokinetics

Croscarmellose sodium is not absorbed in the gastrointestinal tract, as its primary function is to aid in the disintegration of solid dosage forms. After serving its purpose, it is excreted unchanged. The substance does not have a systemic pharmacokinetic profile since it does not enter systemic circulation.

Pregnancy

Croscarmellose sodium is generally considered safe during pregnancy, but consult a healthcare provider for specific recommendations.

Breast-feeding

Croscarmellose sodium is unlikely to pose a risk during breastfeeding; however, consult a healthcare provider for personalized advice.

Storage

Store in a cool, dry place away from moisture and direct sunlight.

Formulations

• Croscarmellose sodium is commonly available as a powder or granule for pharmaceutical use.

Indications

• Lactose intolerance
• As a filler or excipient in pharmaceutical formulations

Dosage

Children: Refer to the BNF for Children for specific dosing information based on age and clinical context.

Adults: Refer to the BNF for specific dosing information based on clinical context.

Mechanism of action

Lactose is metabolized in the intestine by the enzyme lactase into its constituent monosaccharides, glucose and galactose. In individuals with lactase deficiency, unabsorbed lactose passes into the colon, where it is fermented by bacteria, leading to gas production and osmotic effects that contribute to diarrhea.

Pharmacodynamics

The pharmacodynamics of lactose are primarily related to its effects on gastrointestinal function. In healthy individuals, lactose is effectively broken down into glucose and galactose, which are absorbed and utilized for energy. In individuals with lactose intolerance, the unabsorbed lactose can cause osmotic diarrhea and colonic fermentation, leading to discomfort and symptoms associated with lactose intolerance.

Pharmacokinetics

Lactose is not absorbed in the gastrointestinal tract until it is hydrolyzed into glucose and galactose by lactase. The absorption of glucose and galactose occurs in the small intestine. The half-life is not applicable as lactose is not typically administered as a medication but is rather ingested as a natural component of food. Its metabolism primarily occurs in the intestine.

Adverse effects

• Bloating
• Diarrhea
• Abdominal pain
• Flatulence

Precautions

• Use with caution in patients with lactose intolerance.
• Consider potential for gastrointestinal upset in sensitive individuals.

Pregnancy

Lactose is generally considered safe for use during pregnancy. However, consult a healthcare professional for individual advice.

Breast-feeding

Lactose is safe to use while breastfeeding, as it is a natural sugar present in breast milk.

Storage

Store in a cool, dry place, away from direct sunlight.

Formulations

• Powder
• Granules
• Tablets
• Syrup

Indications

• Allergic rhinitis
• Chronic urticaria

Dosage

Children: For children aged 6 to 11 years, the recommended dose is 5 mg once daily. For children aged 2 to 5 years, the dose is 1.25 mg once daily.

Adults: The usual dose for adults is 5 mg once daily.

Mechanism of action

Levocetirizine selectively inhibits histamine H1 receptors. This action prevents histamine from activating the receptor and causing effects such as smooth muscle contraction, increased permeability of vascular endothelium, histidine uptake in basophils, stimulation of cough receptors, and stimulation of flare responses in the nervous system.

Pharmacodynamics

As a second-generation histamine H1 antagonist, levocetirizine effectively reduces various allergic symptoms. It possesses a long duration of action, allowing for once-daily dosing. The therapeutic index is favorable, with studies showing that the maximal nonlethal dose is significantly higher than the therapeutic dose. Caution is advised for activities requiring full alertness and in patients predisposed to urinary retention.

Pharmacokinetics

Levocetirizine is well absorbed after oral administration, with peak plasma concentrations typically reached within approximately 1 hour. It has a volume of distribution of about 0.4 L/kg and is primarily excreted unchanged in the urine. The elimination half-life is approximately 8 to 9 hours, allowing for once-daily dosing.

Contra-indications

• Hypersensitivity to levocetirizine or any of its components
• Severe renal impairment

Adverse effects

• Drowsiness
• Fatigue
• Dry mouth
• Headache
• Gastrointestinal disturbances

Interactions

• CNS depressants may enhance sedative effects
• Alcohol may increase sedation

Precautions

• Caution in patients with a history of urinary retention
• Caution in patients with severe renal impairment
• Avoid operating machinery or driving until you know how levocetirizine affects you

Pregnancy

Levocetirizine should be used in pregnancy only if the potential benefit justifies the potential risk to the fetus.

Breast-feeding

Levocetirizine is excreted in breast milk; caution should be exercised when administering to nursing mothers.

Storage

Store at room temperature, away from moisture and heat.

Formulations

• Tablets
• Oral solution

Indications

• Used as an excipient in tablet formulations
• Used as a bulking agent in capsule formulations
• Used in food products as a thickener or stabilizer

Dosage

Children: Refer to specific product guidelines as dosage will depend on the formulation and the active ingredients.

Adults: Refer to specific product guidelines as dosage will depend on the formulation and the active ingredients.

Mechanism of action

Microcrystalline cellulose acts as a non-digestible filler that enhances the flow properties of powders during the manufacturing of tablets and capsules. It does not have a direct pharmacological action on the body but ensures that the active ingredients are effectively delivered to the patient.

Pharmacodynamics

As a non-active ingredient, microcrystalline cellulose does not exert pharmacodynamic effects typical of active pharmaceutical ingredients. Its primary role is to provide a stable and consistent matrix for the drug, facilitating the release of the active compound once ingested.

Pharmacokinetics

Microcrystalline cellulose is not absorbed in the gastrointestinal tract; it passes through the digestive system largely unchanged. It adds bulk to the stool, which may aid in promoting regular bowel movements. The substance is excreted in feces, where it contributes to dietary fiber intake.

Pregnancy

Data regarding the use of microcrystalline cellulose during pregnancy is limited. It is advisable to consult with healthcare professionals before use.

Breast-feeding

Microcrystalline cellulose is considered safe during breastfeeding, as it is not absorbed systemically.

Storage

Store in a cool, dry place away from direct sunlight and moisture.

Dosage

Children: Refer to specific drug formulations and product labels as purified substances can vary widely in their use and dosing.

Adults: Refer to specific drug formulations and product labels as purified substances can vary widely in their use and dosing.

Mechanism of action

The mechanism of action for purified compounds varies widely depending on the specific substance. Generally, purified drugs exert their effects by interacting with specific biological targets, such as receptors, enzymes, or ion channels, leading to a desired therapeutic effect. This interaction can involve binding to receptors to activate or inhibit signaling pathways, modulating enzymatic activity, or altering physiological processes.

Pharmacodynamics

Pharmacodynamics describes the effects of a drug on the body and the relationship between drug concentration and effect. For purified drugs, this can involve dose-response relationships and the time course of their action. The purified form often enhances potency and reduces variability in response among patients, which can lead to more predictable therapeutic outcomes. The overall effect is determined by the drug's affinity for its target, the efficacy of the drug-receptor interaction, and the downstream signaling pathways activated as a result of this interaction.

Pharmacokinetics

Pharmacokinetics involves the absorption, distribution, metabolism, and excretion (ADME) of a drug. For purified substances, absorption can be more efficient due to the absence of impurities that may affect solubility or stability. Distribution may also be enhanced, leading to higher bioavailability. Metabolism can be influenced by the structure of the purified compound, as it may be metabolized more readily by liver enzymes. Excretion typically occurs through the kidneys or liver, depending on the molecular characteristics of the purified drug.

Pregnancy

Consult with a healthcare professional, as the safety of purified forms of medications during pregnancy may vary depending on the specific substance.

Breast-feeding

Consult with a healthcare professional, as the safety of purified forms of medications during breastfeeding may vary depending on the specific substance.

Storage

Store in a cool, dry place, away from light and moisture, and keep out of reach of children.

Dosage

Children: Refer to the BNF for Children for appropriate paediatric dosing information.

Adults: Refer to the specific BNF guidelines for dosing information as it may vary based on the condition being treated.

Mechanism of action

The mechanism of action for White involves its interaction with specific biological pathways, leading to the desired pharmacological effects. The precise pathways may include modulation of receptor activity or alteration of enzyme function, although specific details are not provided.

Pharmacodynamics

Pharmacodynamics of White includes its effects on the body, including therapeutic effects and potential side effects. As a compound, it may exert its influence on multiple physiological systems, which can lead to changes in symptoms or disease progression.

Pharmacokinetics

Pharmacokinetics of White involves its absorption, distribution, metabolism, and excretion. Understanding these parameters can help predict how the drug behaves in the body, including onset of action and duration of effect. Detailed pharmacokinetic data is not specified.

Mechanism of action

Levocetirizine selectively inhibits histamine H₁ receptors. This action prevents histamine from activating this receptor and causing effects like smooth muscle contraction, increased permeability of vascular endothelium, histidine uptake in basophils, stimulation of cough receptors, and stimulation of flare responses in the nervous system.

Pharmacodynamics

Levocetirizine is a second generation histamine H₁ antagonist used to treat various allergic symptoms. It has a long duration of action as it is generally taken once daily, and a wide therapeutic window as animal studies show the maximal nonlethal dose is over 100x a normal dose. Patients are cautioned to avoid tasks that require complete alertness, avoid alertness, and use caution in patients with factors predisposing urinary retention.