JITRIT-5

Indications

• Moderate to severe rheumatoid arthritis
• Psoriatic arthritis
• Moderate to severe ulcerative colitis
• Ankylosing spondylitis

Dosage

Adults: For rheumatoid arthritis: 5 mg twice daily or 11 mg once daily using modified-release tablets. For ulcerative colitis and other indications, consult specific product literature for guidelines.

Mechanism of action

Tofacitinib acts as a partial and reversible inhibitor of Janus kinases (JAKs), which are critical enzymes in the signaling pathways of pro-inflammatory cytokines. By inhibiting JAKs, it prevents the phosphorylation and activation of signal transducers and activators of transcription (STATs), reducing the transcription of genes involved in inflammation and immune response. This modulation of the JAK-STAT signaling pathway decreases tissue inflammation and joint damage in conditions such as rheumatoid arthritis.

Pharmacodynamics

Clinical trials have shown that tofacitinib effectively targets inflammation in rheumatoid arthritis, with significant improvements in ACR20 responses (20% reduction in joint pain and other measures of arthritis) observed within 2 weeks in some patients. Common adverse effects include headaches, diarrhea, nausea, and upper respiratory infections, while more serious effects can include lymphopenia, neutropenia, anemia, and an increased risk of infections and cancers. Close monitoring for infections, especially tuberculosis, is essential during treatment.

Pharmacokinetics

Tofacitinib is absorbed after oral administration, with peak plasma concentrations typically reached within 1-2 hours. It is primarily metabolized by CYP3A4 enzymes, with a half-life of approximately 3 hours. The drug's exposure can be affected by co-administration with other medications that induce or inhibit CYP enzymes, necessitating careful consideration of drug interactions. Renal impairment can also affect dosing, and caution is advised in patients with moderate to severe renal conditions.

Contra-indications

• Severe hypersensitivity to tofacitinib or any of its excipients
• Severe renal impairment (end-stage renal disease)
• Active infections, including tuberculosis
• History of malignancy, particularly non-melanoma skin cancer

Adverse effects

• Headache
• Diarrhea
• Nausea
• Nasopharyngitis
• Upper respiratory tract infection
• Lymphopenia
• Neutropenia
• Anemia
• Increased risk of serious infections
• Increased risk of malignancies

Interactions

• Ciclosporin: Severe (increases exposure)
• Filgotinib: Severe (increases risk of immunosuppression)
• Tacrolimus: Severe (increases exposure)
• Fluconazole: Unknown (increases exposure)
• Cobicistat: Unknown (increases exposure)
• Dabrafenib: Unknown (decreases exposure)
• Bosentan: Unknown (decreases exposure)
• Idelalisib: Unknown (increases exposure)
• Clarithromycin: Unknown (increases exposure)
• Mitotane: Unknown (decreases exposure)

Precautions

• Screen for tuberculosis and viral hepatitis before treatment
• Monitor for signs of infection during treatment
• Monitor for haematological abnormalities before and during treatment
• Periodic skin examination recommended for patients at increased risk for skin cancer
• Caution in moderate to severe renal impairment

Pregnancy

Avoid due to toxicity observed in animal studies.

Breast-feeding

Avoid; no information available.

Storage

Store at room temperature, away from moisture and light.

Formulations

• 100 mg film-coated tablets
• 200 mg film-coated 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

• Used as a disintegrant in tablet formulations
• Enhances the bioavailability of active pharmaceutical ingredients

Dosage

Children: Refer to the specific formulation guidelines, as dosage will vary based on the active ingredient and formulation type.

Adults: Refer to the specific formulation guidelines, as dosage will vary based on the active ingredient and formulation type.

Mechanism of action

Croscarmellose sodium works by swelling and absorbing water when it comes into contact with gastrointestinal fluids. This swelling leads to the rapid disintegration of the tablet or capsule matrix, facilitating the release and absorption of the active pharmaceutical ingredients.

Pharmacodynamics

Croscarmellose sodium is classified as a superdisintegrant. Its ability to rapidly disintegrate solid dosage forms can significantly enhance the dissolution rate of the active ingredient, which is crucial for achieving therapeutic effects in a timely manner.

Pharmacokinetics

Croscarmellose sodium is not absorbed in the gastrointestinal tract and does not exert pharmacological effects in the body. It is considered non-toxic and is excreted unchanged. Its main role is as an excipient, influencing the formulation's characteristics rather than the pharmacokinetics of the active ingredients.

Precautions

• Use with caution in patients with known hypersensitivity to croscarmellose or its components.

Pregnancy

Safety in pregnancy has not been established. Use only if clearly needed.

Breast-feeding

Caution is advised when using during breastfeeding, as safety has not been established.

Storage

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

Formulations

• Powder
• Granules

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

• 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.

Indications

• Tablet coating
• Granule coating
• Improvement of drug stability
• Taste masking
• Aesthetic enhancement of pharmaceuticals

Dosage

Children: Dosage will depend on the specific formulation and active ingredients of the medication being coated. Refer to the specific product information for guidance.

Adults: Dosage will depend on the specific formulation and active ingredients of the medication being coated. Refer to the specific product information for guidance.

Mechanism of action

Opadry functions primarily as a coating polymer that adheres to the surface of tablets or granules, creating a protective layer. This layer can control the release of the active ingredient and protect it from environmental factors such as moisture and light. The specific composition of Opadry can vary, but it typically includes film-forming agents, plasticizers, and colorants that work together to achieve the desired coating characteristics.

Pharmacodynamics

The pharmacodynamics of Opadry is largely focused on its physical and chemical properties rather than specific biological interactions. The coating alters the dissolution characteristics of the drug, potentially leading to modified release profiles. This can enhance drug bioavailability or control the release rate of the active ingredient, thereby impacting the therapeutic effect.

Pharmacokinetics

As a coating agent, Opadry itself is not absorbed into the systemic circulation and does not have pharmacokinetic properties related to absorption, distribution, metabolism, or excretion of an active pharmaceutical ingredient. Its impact on pharmacokinetics is indirect, as it affects how the active drug is released and absorbed in the gastrointestinal tract.

Pregnancy

Opadry is a film-coating agent, and specific studies on its effects during pregnancy are not well-documented. Generally, it is advisable to use medications cautiously during pregnancy. Consult a healthcare provider for guidance.

Breast-feeding

Limited data are available regarding the safety of Opadry during breastfeeding. It is recommended to consult a healthcare provider before use.

Storage

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

Formulations

• Opadry OY - a coating system for oral solid dosage forms
• Opadry II - a polymer-based coating system for tablet and capsule applications

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

Rheumatoid arthritis is an autoimmune disease characterized by a dysregulation of pro-inflammatory cytokines including IL7, IL15, IL21, IL6, IFN-alpha, and IFN-beta. (3) Cytokines signalling results in tissue inflammation and joint damage by stimulating the recruitment and activation of immune cells via the janus kinase signalling pathway. Tofacitinib is a partial and reversible janus kinase (JAK) inihibitor that will prevent the body from responding to cytokine signals. By inhibiting JAKs, tofacitinib prevents the phosphorylation and activation of STATs. The JAK-STAT signalling pathway is involved in the transcription of cells involved in hematopoiesis, and immune cell function. Tofacitinib works therapeutically by inhibiting the JAK-STAT pathway to decrease the inflammatory response. However, there is evidence to suggest that it may also achieve efficacy via other pathways as well. Tofacitinib citrate, a Janus kinase (JAK) inhibitor, is an immunomodulating agent and a disease-modifying antirheumatic drug (DMARD). JAKs are intracellular enzymes that mediate the signaling of cytokines and growth factors that are important for hematopoiesis and immune function. JAK signaling involves recruitment of signal transducers and activators of transcription (STATs) to cytokine receptors, activation, and subsequent localization of STATs to the nucleus leading to modulation of gene expression. Tofacitinib modulates the signaling pathway at the point of JAKs, preventing the phosphorylation and activation of STATs. Tofacitinib inhibits JAK1 and JAK3 and, to a lesser extent, JAK2. JAK enzymes transmit cytokine signaling through pairing of JAKs (e.g., JAK1/JAK3, JAK1/JAK2, JAK2/JAK2). In vitro, tofacitinib inhibited the activity of JAK1/JAK2, JAK1/JAK3, and JAK2/JAK2 combinations with IC50 (concentration that inhibits activity by 50%) values of 406, 56, and 1377 nM, respectively. The relevance of specific JAK combinations to the therapeutic efficacy of tofacitinib is not known. /Tofacitinib citrate/ Inhibitors of the JAK family of nonreceptor tyrosine kinases have demonstrated clinical efficacy in rheumatoid arthritis and other inflammatory disorders; however, the precise mechanisms by which JAK inhibition improves inflammatory immune responses remain unclear. In this study, we examined the mode of action of tofacitinib (CP-690,550) on JAK/STAT signaling pathways involved in adaptive and innate immune responses. To determine the extent of inhibition of specific JAK/STAT-dependent pathways, we analyzed cytokine stimulation of mouse and human T cells in vitro. We also investigated the consequences of CP-690,550 treatment on Th cell differentiation of naive murine CD4(+) T cells. CP-690,550 inhibited IL-4-dependent Th2 cell differentiation and interestingly also interfered with Th17 cell differentiation. Expression of IL-23 receptor and the Th17 cytokines IL-17A, IL-17F, and IL-22 were blocked when naive Th cells were stimulated with IL-6 and IL-23. In contrast, IL-17A production was enhanced when Th17 cells were differentiated in the presence of TGF-beta. Moreover, CP-690,550 also prevented the activation of STAT1, induction of T-bet, and subsequent generation of Th1 cells. In a model of established arthritis, CP-690,550 rapidly improved disease by inhibiting the production of inflammatory mediators and suppressing STAT1-dependent genes in joint tissue. Furthermore, efficacy in this disease model correlated with the inhibition of both JAK1 and JAK3 signaling pathways. CP-690,550 also modulated innate responses to LPS in vivo through a mechanism likely involving the inhibition of STAT1 signaling. Thus, CP-690,550 may improve autoimmune diseases and prevent transplant rejection by suppressing the differentiation of pathogenic Th1 and Th17 cells as well as innate immune cell signaling.

Pharmacodynamics

Tofacitinib targets inflammation present in rheumatoid arthritis by inhibiting the janus kinases involved in the inflammatory response pathway. In placebo controlled trials of rheumatoid arthritis patients receiving 5mg or 10mg of tofacitinib twice daily, higher ACR20 responses were observed within 2 weeks in some patients (with ACR20 being defined as a minimum 20% reduction in joint pain or tenderness and 20% reduction in arthritis pain, patient disability, inflammatory markers, or global assessments of arthritis by patients or by doctors, according to the American College of Rheumatology (ACR) response criteria list), and improvements in physical functioning greater than placebo were also noted. Common known adverse effects of tofacitinib include headaches, diarrhea, nausea, nasopharyngitis and upper respiratory tract infection. More serious immunologic and hematological adverse effects have also been noted resulting in lymphopenia, neutropenia, anemia, and increased risk of cancer and infection. Before initiations of tofacitinib patients should be tested for latent infections of tuberculosis, and should be closely monitored for signs and symptoms of infection (fungal, viral, bacterial, or mycobacterial) during therapy. Therapy is not to be started in the presence of active infection, systemic or localized, and is to be interrupted if a serious infection occurs. Tofacitinib has been associated with an increased risk of lymphomas, such as Epstein-Barr virus associated lymphomas, and other malignancies (including lung, breast, gastric, and colorectal cancers). It is recommended to monitor lymphocytes, neutrophils, hemoglobin, liver enzymes, and lipids. Tofacitinib use is associated with a rapid decrease in C-reactive protein (CRP), dose dependent decreases in natural killer cells, and dose dependent increases in B cells. Depression in C-reactive protein levels continue after 2 weeks of tofacitinib discontinuation and suggest that pharmacodynamic activity last longer than pharmacokinetic half life.