BECOACTIN TABLETS

Indications

• Papulopustular rosacea
• Inflammatory acne vulgaris

Dosage

Children: Refer to the BNF for Children for specific dosing recommendations.

Adults: For papulopustular rosacea, apply daily for up to 4 months. The treatment course may be repeated; discontinue if no improvement is observed after 3 months. For inflammatory acne vulgaris, apply twice daily, reduced to once daily or alternate days if irritation occurs.

Mechanism of action

Nicotinamide exhibits anti-inflammatory effects by inhibiting the release of pro-inflammatory cytokines and enhancing the barrier function of the skin. It is also involved in the NAD salvage pathway, which is essential for maintaining cellular energy levels and promoting cell repair mechanisms. Additionally, nicotinamide contributes to the synthesis of coenzymes involved in metabolic processes, including the conversion of niacin into NAD+.

Pharmacodynamics

Nicotinamide is known for its ability to improve skin hydration and reduce transepidermal water loss. It has been shown to decrease the appearance of acne lesions and rosacea by modulating inflammatory responses and accelerating cell turnover. Its antioxidant properties also help to protect the skin from oxidative stress and UV damage.

Pharmacokinetics

When applied topically, nicotinamide is absorbed through the skin layers, with minimal systemic absorption. Its peak plasma concentrations are generally low, and the drug has a half-life that varies depending on the route of administration. The metabolism of nicotinamide occurs primarily in the liver, where it is converted into its active forms, including NAD+. The elimination route is via the kidneys, with metabolites excreted in urine.

Contra-indications

• Pregnancy
• Severe acne involving large areas
• Severe skin reactions

Adverse effects

• Sunburn
• Skin reactions (common or very common)
• Cheilitis
• Eyelid oedema
• Flushing
• Dry skin
• Eye irritation
• Photosensitivity reactions
• Transient skin pigmentation changes

Interactions

• Clindamycin
• Topical retinoids
• Abrasive cleaners
• Comedogenic cosmetics

Precautions

• Avoid exposure to UV light, including sunlight and sunlamps
• Wash hands immediately after use
• Avoid contact with eyes and mucous membranes
• Use moisturizers to reduce the risk of skin irritation
• Discontinue treatment if severe irritation occurs

Pregnancy

Avoid use during pregnancy due to potential risks, as limited information is available regarding toxicity.

Breast-feeding

Amount of drug in milk after topical application is probably too small to be harmful; ensure infant does not come in contact with treated areas.

Storage

Store at room temperature away from moisture and light.

Formulations

• Cream
• Gel

Indications

• Allergic conditions
• Hay fever
• Urticaria
• Pruritus
• Appetite stimulation

Dosage

Children: For children aged 6 months to 5 years, the dose is 5-15 mg daily in divided doses, adjusted according to weight, with a maximum of 2 mg/kg per day. For children aged 6-17 years weighing up to 40 kg, the initial dose is 15-25 mg daily in divided doses, adjusted as necessary to a maximum of 2 mg/kg per day. For those weighing 40 kg and above, the initial dose is 15-25 mg daily in divided doses, increased if necessary to 50-100 mg daily.

Adults: Initially, 25 mg daily, taken at night; may be increased if necessary to 25 mg 3-4 times a day. Maximum dose is 32 mg per day.

Mechanism of action

Cyproheptadine acts as a competitive antagonist at histamine H1 receptors, thereby inhibiting the action of histamine, which is responsible for allergic symptoms. Additionally, it may also block serotonin receptors, contributing to its appetite-stimulating effects.

Pharmacodynamics

The drug exhibits sedative effects by crossing the blood-brain barrier, leading to central nervous system depression. It can also produce anticholinergic effects, such as dry mouth and urinary retention, due to its action on muscarinic receptors. The sedative properties can impair the performance of skilled tasks and may be potentiated by alcohol consumption.

Pharmacokinetics

Cyproheptadine is well-absorbed from the gastrointestinal tract and undergoes hepatic metabolism. Its elimination half-life is approximately 8-12 hours, and it is excreted primarily in urine. The onset of action is typically within 1-2 hours, with effects lasting for several hours.

Contra-indications

• Acute porphyrias
• Prolonged QT-interval
• Risk factors for QT prolongation

Adverse effects

• Drowsiness
• Dizziness
• Dry mouth
• Nausea
• Constipation
• Headache
• Palpitations
• Tachycardia
• Fatigue
• Irritability
• Paradoxical excitability
• Tremor

Interactions

• Antihistamines
• Sedating agents
• Alcohol

Precautions

• Use with caution in the elderly
• Patients with epilepsy
• Prostatic hypertrophy
• Pyloroduodenal obstruction
• Susceptibility to angle-closure glaucoma
• Urinary retention

Pregnancy

Most manufacturers of antihistamines advise avoiding their use during pregnancy; however, there is no evidence of teratogenicity. Use in the latter part of the third trimester may cause adverse effects in neonates.

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 direct sunlight. Keep out of reach of children.

Formulations

• Oral suspension
• Tablets (4 mg)

Indications

• Bladder irrigation during urological surgery
• Irrigation for transurethral resection of the prostate gland
• Irrigation for bladder tumors

Dosage

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

Adults: Refer to the product literature for specific dosing information.

Mechanism of action

Glycine binds to strychnine-sensitive and strychnine-insensitive glycine receptors in the central nervous system. The strychnine-sensitive receptor is a chloride channel that enhances inhibitory neurotransmission. This action may contribute to glycine's potential antispastic effects. Additionally, glycine potentiates NMDA receptor-mediated neurotransmission, which may have implications in managing certain neurological conditions, such as neuroleptic-resistant negative symptoms in schizophrenia.

Pharmacodynamics

Glycine plays a crucial role in various biological functions, including energy metabolism and immune response. It is involved in hormone synthesis and helps in modulating neurotransmitter release, particularly in inhibitory pathways. Glycine's ability to enhance chloride conductance in neurons contributes to its antispastic properties and its potential to mitigate oxidative stress in immune responses.

Pharmacokinetics

Glycine is absorbed readily in the gastrointestinal tract and is utilized by the body for protein synthesis and other metabolic functions. The distribution of glycine in the body is widespread, as it is present in various tissues. Glycine is metabolized in the liver and other tissues, with excretion primarily occurring via the kidneys. The pharmacokinetics of glycine can be influenced by factors such as age, renal function, and overall health status.

Adverse effects

• Fluid overload
• Electrolyte imbalance
• Nausea
• Vomiting
• Headache
• Hypotension

Precautions

• Monitor for signs of fluid overload during irrigation
• Use caution in patients with pre-existing electrolyte imbalances
• Careful consideration in patients with renal impairment

Pregnancy

Glycine is generally considered safe for use during pregnancy when used as an irrigation solution, but risks should be discussed with a healthcare provider.

Breast-feeding

Glycine is likely safe during breastfeeding, but limited data is available. Consultation with a healthcare professional is advisable.

Storage

Store in a cool, dry place. Protect from light. Do not freeze.

Formulations

• Glycine 1.5% irrigation solution 3 litre Easyflow bags
• Glycine 1.5% irrigation solution 1 litre Flowfusor bottles
• Glycine 1.5% irrigation solution 1 litre Easyflow bags
• Glycine 1.5% irrigation solution 2 litre Flowfusor bottles

Indications

• Allergic rhinitis
• Allergic conjunctivitis
• Urticaria
• Angioedema
• Anaphylaxis (as adjunct therapy)
• Appetite stimulation in certain conditions

Dosage

Children: Refer to BNF for Children for appropriate pediatric dosing, as it varies by age and condition. Generally, doses may start at 0.25 mg/kg for younger children, but specific guidelines should be

Adults: The usual adult dose for allergic conditions is 4 mg three times daily, which may be increased to a maximum of 12 mg per day as needed. For appetite stimulation, the starting dose is often 4 mg taken once or twice daily.

Mechanism of action

Cyproheptadine exerts its effects by competing with free histamine and serotonin for binding at their respective receptors. Its action as an H1 blocker is complemented by its antagonism of serotonin at 5-HT2A receptors, particularly influencing the appetite center in the hypothalamus. This dual action accounts for its appetite-stimulating properties and mitigates several pharmacodynamic effects of serotonin.

Pharmacodynamics

Cyproheptadine antagonizes several effects of serotonin and histamine, including bronchoconstriction and vasodepression. Its efficacy in combatting histamine-mediated effects has been established, although the details regarding its role in preventing anaphylactic shock remain unclear, likely linked to its anti-serotonergic activity. The drug's sedative properties arise from its central nervous system effects.

Pharmacokinetics

Cyproheptadine is well-absorbed after oral administration. It is metabolized in the liver, with a variable half-life and is primarily excreted in urine. The onset of action typically occurs within one to two hours, and the duration of action can last up to 12 hours. The pharmacokinetic profile may be influenced by individual metabolic variations.

Adverse effects

• Drowsiness
• Dizziness
• Dry mouth
• Constipation
• Blurred vision
• Increased appetite

Interactions

• cyproheptadine+metyrapone: Severe (decreases effects)
• cyproheptadine+fenfluramine: Unknown (decreases efficacy)

Precautions

• Caution in patients with glaucoma
• Caution in patients with prostate hypertrophy
• Use with caution in elderly patients due to increased sensitivity

Pregnancy

Cyproheptadine should only be used during pregnancy if the potential benefit justifies the potential risk to the fetus. Limited data are available on its safety.

Breast-feeding

Cyproheptadine is excreted in breast milk. Caution is advised when administered to breastfeeding mothers.

Storage

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

Formulations

• Tablets
• Syrup

Indications

• Malabsorption syndromes
• Crohn's disease
• Cystic fibrosis
• Short bowel syndrome
• Severe food allergies
• Inability to meet nutritional needs through standard diets

Dosage

Children: Refer to specific formulations for dosing, as paediatric dosages depend on the product and the child's nutritional needs.

Adults: Refer to specific formulations for dosing, as adult dosages vary based on the product used and the patient's nutritional requirements.

Mechanism of action

Elemental formulations provide nutrients in their simplest forms, which are readily absorbed in the small intestine. This bypasses complex digestive processes, making them suitable for individuals with compromised digestion or absorption capabilities. The nutrients in these formulations include amino acids, simple carbohydrates, and fatty acids, which can be directly utilized by the body's metabolic pathways.

Pharmacodynamics

Elemental formulations help restore nutritional balance by supplying essential macronutrients and micronutrients needed for metabolic processes. They support growth, maintain energy levels, and promote healing in patients with malabsorption or increased nutritional needs. The bioavailability of nutrients in elemental forms is typically high, allowing for efficient uptake and utilization by the body.

Pharmacokinetics

Following administration, elemental nutrients are absorbed in the gastrointestinal tract, primarily in the jejunum and ileum. The rate of absorption can vary based on the specific formulation and the individual's gastrointestinal health. Once absorbed, these nutrients enter systemic circulation and are transported to various tissues for utilization in metabolic processes. The elimination of unabsorbed nutrients occurs primarily through feces.

Adverse effects

• Nausea
• Vomiting
• Diarrhea
• Constipation
• Stomach cramps
• Dark stools
• Metallic taste
• Allergic reactions

Precautions

• Use with caution in patients with a history of gastrointestinal disorders.
• Monitor for signs of iron overload in patients receiving multiple iron products.
• Assess for the need for supplementation in patients with conditions causing malabsorption.

Pregnancy

Iron is essential during pregnancy, but supplementation should be guided by clinical need and under healthcare supervision.

Breast-feeding

Iron is excreted in breast milk; supplementation may be necessary depending on maternal iron status.

Storage

Store in a cool, dry place, away from direct sunlight and moisture. Keep out of reach of children.

Formulations

• Oral tablets
• Liquid formulations
• Injectable solutions

Indications

• Vitamin deficiency syndromes (e.g., scurvy for vitamin C deficiency, rickets for vitamin D deficiency)
• Support for immune function
• Antioxidant support
• Bone health maintenance
• Vision health
• Energy metabolism support

Dosage

Children: Refer to the BNF for Children for specific vitamin dosing guidelines, which depend on age and nutritional requirements.

Adults: Refer to specific vitamin guidelines as dosage varies significantly depending on the type of vitamin and individual needs.

Mechanism of action

Vitamins function primarily as coenzymes or precursors for coenzymes in enzymatic reactions. For instance, B vitamins are involved in energy metabolism, while vitamins A, C, D, E, and K support various physiological functions including vision, antioxidant activity, calcium regulation, and blood clotting. Each vitamin has a unique mechanism of action based on its structure and role in the body.

Pharmacodynamics

Vitamins exert their effects at the cellular level, influencing metabolic pathways, gene expression, and immune responses. For example, vitamin D regulates calcium and phosphate homeostasis, while vitamin A is crucial for vision and immune function. Deficiencies in vitamins can lead to a range of disorders, highlighting their importance in maintaining health.

Pharmacokinetics

The pharmacokinetics of vitamins vary widely. Fat-soluble vitamins (A, D, E, and K) are stored in liver and adipose tissues and can be released into circulation as needed. Water-soluble vitamins (B-complex and C) are not stored and must be consumed regularly, with excess amounts excreted in urine. Absorption rates, half-lives, and distribution can also differ based on the specific vitamin and individual metabolic factors.

Interactions

• tretinoin+vitamin: Severe (increases risk of vitamin toxicity)
• retinoids+vitamin: Severe (increases risk of vitamin toxicity)
• retinoids+vitamin: Moderate (increases risk of toxicity)
• carbamazepine+vitamin: Unknown (decreases effects)
• cobicistat+vitamin: Unknown (increases exposure)
• vitamin D substances+digoxin: Unknown (increases risk of toxicity)
• idelalisib+vitamin: Unknown (increases exposure)
• clarithromycin+vitamin: Unknown (increases exposure)

Pregnancy

Consult healthcare professional before use. Vitamin supplementation during pregnancy should be carefully managed to avoid hypervitaminosis.

Breast-feeding

Consult healthcare professional before use. Some vitamins can pass into breast milk and may affect the infant.

Storage

Store in a cool, dry place, away from direct sunlight. Ensure it is kept out of reach of children.

Formulations

• {'name': 'Vitamin A', 'form': 'Capsule', 'strength': '10000 IU'}
• {'name': 'Vitamin D', 'form': 'Tablet', 'strength': '1000 IU'}
• {'name': 'Vitamin E', 'form': 'Softgel', 'strength': '400 IU'}

Mechanism of action

In the CNS, there exist strychnine-sensitive glycine binding sites as well as strychnine-insensitive glycine binding sites. The strychnine-insensitive glycine-binding site is located on the NMDA receptor complex. The strychnine-sensitive glycine receptor complex is comprised of a chloride channel and is a member of the ligand-gated ion channel superfamily. The putative antispastic activity of supplemental glycine could be mediated by glycine's binding to strychnine-sensitive binding sites in the spinal cord. This would result in increased chloride conductance and consequent enhancement of inhibitory neurotransmission. The ability of glycine to potentiate NMDA receptor-mediated neurotransmission raised the possibility of its use in the management of neuroleptic-resistant negative symptoms in schizophrenia. Animal studies indicate that supplemental glycine protects against endotoxin-induced lethality, hypoxia-reperfusion injury after liver transplantation, and D-galactosamine-mediated liver injury. Neutrophils are thought to participate in these pathologic processes via invasion of tissue and releasing such reactive oxygen species as superoxide. In vitro studies have shown that neutrophils contain a glycine-gated chloride channel that can attenuate increases in intracellular calcium and diminsh neutrophil oxidant production. This research is ealy-stage, but suggests that supplementary glycine may turn out to be useful in processes where neutrophil infiltration contributes to toxicity, such as ARDS. HYPERPOLARIZATION OF MOTONEURONS PRODUCED BY IONTOPHORETIC APPLICATION OF GLYCINE IS RELATIVELY TRANSIENT BUT APPROACHES THE EQUILIBRIUM POTENTIAL FOR THE INDIRECTLY ACTIVATED INHIBITORY POSTSYNAPTIC POTENTIAL...TESTS WITH GABA... INDICATE SIMILAR ELECTROPHYSIOLOGICAL EFFECTS & SIMILAR INCR IN CL- CONDUCTANCE. MAJOR EVIDENCE THAT FAVORS GLYCINE AS MEDIATOR OF INTRASPINAL POSTSYNAPTIC INHIBITION IS THE SELECTIVE ANTAGONISM OF ITS EFFECTS BY STRYCHNINE. ... GLYCINE ALSO APPEARS TO BE MOST LIKELY TRANSMITTER FOR INHIBITORY INTERNEURONS IN RETICULAR FORMATION BUT NOT IN CUNEATE NUCLEUS.

Pharmacodynamics

Helps trigger the release of oxygen to the energy requiring cell-making process; Important in the manufacturing of hormones responsible for a strong immune system.

Mechanism of action

Cyproheptadine appears to exert its antihistamine and antiserotonin effects by competing with free histamine and serotonin for binding at their respective receptors. Antagonism of serotonin on the appetite center of the hypothalamus may account for cyproheptadine's ability to stimulate the appetite. CYPROHEPTADINE...IS A SEROTONIN & HISTAMINE ANTAGONIST... ... It is an effective H1 blocker. Cyproheptadine also has prominent 5-H blocking activity on smooth muscle by virtue of its binding to 5-HT2A receptors. ... It has weak anticholinergic activity and possess mild central depressant properties.

Pharmacodynamics

Cyproheptadine has been observed to antagonize several pharmacodynamic effects of serotonin in laboratory animals, including bronchoconstriction and vasodepression, and has demonstrated similar efficacy in antagonizing histamine-mediated effects. The reason for its efficacy in preventing anaphylactic shock has not been elucidated, but appears to be related to its anti-serotonergic effects.