NEO-RAL

Indications

• Oral candidiasis
• Perioral fungal infections
• Oropharyngeal candidiasis

Dosage

Children: 100,000 units by mouth 4 times a day, usually for 7 days, continued for 48 hours after lesions have resolved.

Adults: 100,000 units by mouth 4 times a day, usually for 7 days, continued for 48 hours after lesions have resolved.

Mechanism of action

Nystatin is a channel-forming ionophore that binds to ergosterol, a sterol found in fungal cell membranes, creating membrane-spanning pores. This disrupts the membrane's integrity, resulting in the leakage of intracellular components and loss of electrochemical gradients essential for cell function, leading to cell death.

Pharmacodynamics

Nystatin exhibits both fungistatic and fungicidal activity against a wide range of yeasts and yeast-like fungi, particularly _Candida albicans_. Resistance is minimal with _Candida albicans_ but may develop in other _Candida_ species. It is ineffective against bacteria, protozoa, or viruses and has significant systemic toxicity, limiting its use to topical and oral applications.

Pharmacokinetics

Nystatin is poorly absorbed from the gastrointestinal tract, which allows it to exert its effects locally within the gut and oral cavity. Because of its limited systemic absorption, it is primarily used for local treatment of fungal infections. The drug is not metabolized systemically and is excreted unchanged in the feces.

Contra-indications

• Infants with impaired swallowing
• Acute porphyrias

Adverse effects

• Abdominal distress
• Angioedema
• Diarrhoea
• Face oedema
• Nausea
• Sensitisation
• Skin reactions
• Stevens-Johnson syndrome
• Vomiting

Precautions

• Caution in patients with acute porphyrias
• Use with care in patients with a history of hypersensitivity to nystatin or other polyene antifungals

Pregnancy

Nystatin is generally considered safe in pregnancy; however, it should be used only if clearly needed and prescribed by a healthcare provider.

Breast-feeding

Nystatin is excreted in breast milk but is considered safe for use during breastfeeding as it is poorly absorbed systemically.

Storage

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

Formulations

• Nystatin oral suspension 100,000 units/ml
• Nystatin tablets
• Nystatin capsules

Dosage

Children: Refer to specific drug guidelines as dosing in units varies based on the drug and its clinical application.

Adults: Refer to specific drug guidelines as dosing in units varies based on the drug and its clinical application.

Mechanism of action

The mechanism of action of drugs measured in units depends on the specific substance. For example, insulin (measured in units) facilitates glucose uptake in cells by binding to insulin receptors, activating a signaling pathway that enhances glucose transporter translocation to the cell membrane. This results in a decrease in blood glucose levels. Similarly, other drugs measured in units may exert their effects through receptor binding, enzyme catalysis, or other biochemical interactions.

Pharmacodynamics

Pharmacodynamics describes the effects of the drug on the body and includes the relationship between drug concentration and effect. For substances measured in units, the pharmacodynamic response may be variable and is often dependent on the individual’s sensitivity to the drug, receptor availability, and other pharmacological factors. For instance, the effect of 1 unit of insulin can vary significantly among individuals based on their insulin sensitivity and metabolic state.

Pharmacokinetics

Pharmacokinetics refers to the absorption, distribution, metabolism, and excretion of drugs. For substances measured in units, the pharmacokinetic profile can differ widely. For instance, insulin is rapidly absorbed when administered subcutaneously, distributed throughout the body, metabolized by the liver and kidneys, and its effects can be observed within minutes. Other drugs may have different absorption rates, half-lives, and routes of elimination.

Pregnancy

Consult a healthcare professional. The safety of this drug during pregnancy has not been established.

Breast-feeding

Consult a healthcare professional. The safety of this drug during breastfeeding has not been established.

Storage

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

Mechanism of action

Nystatin is a channel-forming ionophore, meaning it exerts its therapeutic effect via formation of a membrane-spanning pore in the fungal plasma membrane. The formation of this pore results in a change in membrane permeability that allows for leakage of intracellular contents and the subsequent disruption of electrochemical gradients necessary for proper cell function. Selectivity for fungal cells over mammalian cells is due to nystatin’s greater binding affinity for ergosterol, a key sterol found in fungal cell walls, as opposed to its mammalian counterpart, cholesterol. Nystatin exerts its antifungal activity by binding to sterols in the fungal cell membrane. The drug is not active against organisms (e.g., bacteria) that do not contain sterols in their cell membrane. As a result of this binding, the membrane is no longer able to function as a selective barrier, and potassium and other cellular constituents are lost. ... /Antimicrobial/ agents that act directly on the cell membrane of the microorganism, affecting permeability and leading to leakage of intracellular compounds; these include ... the polyene antifungal agents nystatin ... which bind to cell-wall sterols ...

Pharmacodynamics

Nystatin is an antifungal that is both fungistatic and fungicidal in vitro against a wide variety of yeasts and yeast-like fungi. It exerts its antifungal effects via disruption of the fungal cell membrane. Resistance to nystatin is minimal in _Candida albicans_, but tends to develop in other species of _Candida_. Nystatin carries no significant activity against bacteria, protozoa, or viruses. It carries significant systemic toxicity and is currently unavailable in a formula appropriate for systemic use - its efficacy is currently restricted, therefore, to topical, oral, and gastrointestinal infections.