Synalar rectal

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Synalar rectal

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Medically reviewed

Marina Burgos

Last updated on 10/01/2026

This page provides general, reference-level information compiled from official medical sources. It is not a substitute for professional medical advice, diagnosis, or treatment. For decisions about your health, please consult a qualified healthcare professional.

Overview of Synalar rectal

Quick Facts

Property Description
Active ingredients Fluocinonide, Lidocaine Hydrochloride, Bismuth Subgallate, Menthol
Form Rectal Ointment or Suppository
Pharmacological class Combination drug, Topical Corticosteroid, Local Anesthetic, Astringent
Common use Symptomatic relief of anorectal disorders
Origin Synthetic and Naturally derived components

Synalar rectal is a specialized multi-component rectal formulation that is primarily classified as an Anti-hemorrhoidal preparation. It is engineered as a Fixed-Dose Combination (FDC) product, integrating four distinct active ingredients into a single dosage form suitable for topical rectal administration. This complex composition is clinically recognized for providing broad-spectrum local relief, a key differentiating factor from single-agent therapies.

What Type of Medicine is Synalar Rectal and What is its Purpose?

Synalar rectal is a combination drug designed for comprehensive proctological treatment by addressing multiple symptoms concurrently. Its general therapeutic purpose is to provide immediate, powerful symptomatic relief for the inflammation, pain, and itching associated with anorectal disorders. The preparation’s complexity allows it to achieve combined effects through multiple pharmacological class agents, utilizing both a potent corticosteroid and a local anesthetic in a single preparation. This strategy is designed to provide rapid mitigation of the most uncomfortable symptoms by targeting different pathways of distress.

Synalar Rectal Composition: Active Ingredients and Form

The composition of Synalar rectal is defined by four core active ingredients, each contributing a necessary action. The formulation contains Fluocinonide, categorized as a high-potency corticosteroid, and Lidocaine Hydrochloride, which is an amide-type Local Anesthetic. These primarily synthetic compounds are combined with Bismuth Subgallate, an astringent and protective agent, and Menthol, a counterirritant component derived from natural sources. The unique blend is delivered via a Rectal ointment or Rectal suppository form, with the choice of form offering flexibility in patient application.

How the Combination Delivers Comprehensive Symptomatic Relief

The objective of this multi-component approach is to produce concurrent anti-inflammatory action, local analgesia, and membrane protective action at the affected tissue. This synergy ensures rapid numbing of pain and burning sensations, combined with the reduction of severe inflammation and swelling, and a soothing, cooling effect that contributes significantly to pruritus relief. The specific combination of a high-potency steroid with the multifaceted benefits of the other three components represents a strategic design intended to resolve the multi-symptomatic nature of the condition more efficiently than products lacking this depth of active ingredients.

Regulatory References

  1. MedlinePlus: Hemorrhoids

What side effects are possible with Synalar rectal?

Possible Side Effects and Safety Information

This multi-component rectal preparation’s safety profile, as documented in regulatory sources, is structured around potential effects of its active ingredients, primarily the high-potency corticosteroid, Fluocinonide, and the local anesthetic, Lidocaine.

Adverse reactions are classified by regulatory authorities based on the affected System-Organ Classes (SOC) and documented frequency, and are generally divided into local and systemic effects.

Local Adverse Reactions

The most commonly documented adverse reactions, often classified as Common in regulatory labeling, are related to the application site. These include localized effects such as burning, irritation, and pruritus (itching). Prolonged use of the potent corticosteroid is formally associated with potential changes to the perianal tissue, including skin atrophy (thinning), striae (stretch marks), and hypopigmentation.

Potential Systemic Safety Concerns

The most significant safety considerations are related to the potential for systemic absorption, which is particularly relevant during prolonged use or application over damaged tissue. Serious adverse reactions officially documented include the risk of Hypothalamic-Pituitary-Adrenal (HPA) Axis Suppression, a form of adrenal suppression, and manifestations consistent with Cushing’s syndrome. These endocrine disorders are consequences of high systemic exposure to the corticosteroid component.

Furthermore, systemic absorption of the local anesthetic, Lidocaine, may rarely lead to Nervous System Disorders (e.g., dizziness) or Cardiac Disorders (e.g., bradycardia), especially if high plasma concentrations are reached.

Population-Specific Safety Notes

Regulatory documentation highlights that pediatric patients may exhibit greater susceptibility to systemic corticosteroid effects, such as HPA axis suppression, due to their large skin surface area-to-body mass ratio. Use is formally restricted in the presence of untreated local infections (bacterial, viral, or fungal), as the steroid component may obscure symptoms or exacerbate the underlying infection.

Overdose and Emergency Response

Overdose and When to Seek Help

Overdose with Synalar (fluocinolone acetonide) is generally associated with prolonged or excessive use rather than a single large exposure. Since fluocinolone is a corticosteroid, the primary risk of overuse is the systemic absorption of the medicine through the skin or rectal lining.

Documented Overdose Manifestations

Excessive systemic absorption can lead to the following manifestations, as noted in official regulatory documents:

  • Hypothalamic-Pituitary-Adrenal (HPA) Axis Suppression: The main concern, representing impaired adrenal gland function.
  • Manifestations of Cushing's Syndrome: A disorder caused by high levels of cortisol (or similar corticosteroids).
  • Metabolic Changes: Hyperglycemia (high blood sugar) and glucosuria (sugar in the urine).

When to Seek Medical Help

Medical intervention is centered on managing and monitoring systemic effects:

  • Monitoring: Patients using the product over large areas or for extended periods should be evaluated periodically (e.g., via HPA axis tests) for evidence of systemic absorption or suppression.
  • Action for HPA Suppression: If HPA axis suppression is confirmed by a healthcare provider, the official guidance is to attempt to withdraw the drug, reduce its frequency, or substitute a less potent steroid.
  • Steroid Withdrawal: Symptoms of steroid withdrawal may occur upon discontinuation and may require supplemental systemic corticosteroids from a healthcare professional.

Pediatric patients are noted to be more susceptible to HPA axis suppression and systemic toxicity due to their larger skin surface area to body weight ratio.

Therapeutic Uses of Synalar rectal

The Synalar rectal preparation is primarily used to address the heightened, disruptive symptoms associated with acute anorectal disorders, providing supportive symptomatic management to ease patient distress during symptomatic episodes. It is relevant in clinical settings marked by the sudden escalation or recurrent manifestation of significant discomfort. The use of locally applied corticosteroid products for the short-term management of symptoms related to internal or external hemorrhoids is supported by general therapeutic guidance.

It is commonly used across conditions characterized by periods of heightened symptoms, most notably symptomatic hemorrhoidal disease, perianal eczema, and anal fissures. The combination formulation helps address symptom clusters that involve local tissue inflammation and may assist with easing swelling, intense pain, burning, and persistent pruritus ani. This formulation provides short-term symptomatic assistance to help ease the overall burden of these disruptive manifestations.

“The treatment is applied in contexts where severe sensory distress is the main concern, focusing on symptoms that create noticeable functional strain.”


Quick Fact: Relief for Acute Symptom Clusters
Primary Focus Inflammation, Pain, and Severe Itching
Use Scenario Acute flare-ups of chronic anorectal conditions
Patient Benefit Supports general well-being and functional stability

Eligibility and Restrictions for Use

The eligibility profile for Synalar rectal, a combination product containing a potent corticosteroid (Fluocinonide) and a local anesthetic (Lidocaine), is strictly defined by government regulatory labeling for its components.

Eligibility Status Official Restriction
Contraindicated Patients with a known history of hypersensitivity or allergy to any component of the formulation, or to local anesthetics of the amide type, are strictly prohibited from using this medicine.
Restricted Use is prohibited if a local infection is present and uncontrolled. Administration must be limited; use in an extensive manner (large amounts) or for prolonged periods (long durations) is explicitly prohibited.

Age and Physiological Limitations

  • Pediatric Patients: Use is restricted due to children's greater susceptibility to systemic toxicity, such as HPA axis suppression. Regulatory labeling mandates that administration be limited to the least effective amount, and the use of occlusive dressings, including tight-fitting diapers, is strictly prohibited over the application site.
  • Pregnancy and Lactation: Use during pregnancy is restricted; it should only be administered if the potential benefit justifies the potential risk to the fetus. Caution is required in nursing mothers, as the systemic absorption of the active ingredients into breast milk is not fully established.
  • Condition-Specific Use: Caution is advised for patients with severe hepatic impairment due to the risk of toxic accumulation of the Lidocaine component. Caution is also required in patients with diabetes mellitus because of the risk of elevated blood glucose levels from the absorbed corticosteroid.

What should I know about interactions with other medicines?

Interaction Map: Interactions with other medicines and products — official regulatory information for Synalar rectal

Interaction scope

Category Description based on Official Regulatory Documentation
Medicinal product categories with documented interactions: Strong CYP enzyme inhibitors (CYP3A4 and CYP1A2); Antiarrhythmic Drugs; Beta-Adrenergic Blockers; Tetracycline Antibiotics.
Specific interacting medicines (if explicitly listed): Cimetidine, Fluvoxamine, Propranolol, Amiodarone, Quinidine, and strong CYP3A4 inhibitors (e.g., Ketoconazole, Ritonavir).
Mechanistic basis of interactions (only if stated in label): Reduced metabolic clearance via inhibition of CYP enzymes; Reduced hepatic blood flow; Chelation; Pharmacodynamic additive effects.
Timing-based interaction rules (if applicable): Co-administration with Tetracycline Antibiotics requires a separation of at least two hours to prevent the chelation-mediated reduction of antibiotic systemic absorption by the Bismuth component.
Population-specific interaction notes (if applicable): Patients with documented Severe Hepatic or Renal Impairment face a higher risk of accumulation and toxic phenomena of the Lidocaine component due to reduced clearance.
Interaction-related restrictions: Co-administration with more than one corticosteroid-containing product is restricted due to the potential for increased total systemic absorption and interaction risk of the Fluocinonide component.

Interaction classifications (high-level)

Classification Field Regulatory Assessment
Interaction severity classification (as defined in official documents): Clinically significant interactions requiring monitoring or modification are defined for CYP inhibitors and Antiarrhythmic Drugs.
Regulatory basis (EMA / FDA / etc.): US Food and Drug Administration (FDA) Prescribing Information and associated government drug monographs.
Interaction-context constraints (as defined in official documents): Interactions are contingent on the systemic absorption of the Lidocaine and Fluocinonide components.

Resulting interaction structure

Official interaction statements:

  • Co-administration with strong CYP3A4 inhibitors may decrease the clearance of the systemically absorbed Fluocinonide component, increasing its plasma exposure.
  • Co-administration with CYP3A4 and/or CYP1A2 inhibitors (e.g., Fluvoxamine, Cimetidine) is documented to increase the plasma AUC and Cmax of the Lidocaine component by reducing its metabolic clearance.
  • The use of the Lidocaine component concurrently with other Antiarrhythmic Drugs (e.g., Amiodarone) may result in documented additive cardiac effects.
  • Non-drug exposure modification includes documented warnings regarding Grapefruit or Grapefruit Juice which may increase the plasma concentrations of the Lidocaine component.

Connection to the overall interaction profile (2–4 sentences):

The regulatory interaction profile is defined by two primary concerns: pharmacokinetic changes due to enzyme inhibition/induction and pharmacodynamic effects (additive cardiac risk) tied to the absorbed Lidocaine component. This structure includes specific timing rules mandated by the Bismuth component's chelating properties, as well as population-specific warnings for those with impaired organ function who face a higher risk of accumulation.

Mechanism of Action

Synalar rectal contains fluocinolone acetonide, a synthetic glucocorticoid that operates as an agonist at the intracellular Glucocorticoid Receptor (GR) within targeted rectal and perianal tissue cells.

Following cell membrane penetration, fluocinolone acetonide binds to the cytosolic GR, inducing a conformational change that promotes the dissociation of stabilizing chaperone proteins. The resulting receptor-ligand complex then translocates into the cell nucleus. Within the nucleus, the complex functions as a modified transcription factor, binding to specific DNA sequences known as Glucocorticoid Response Elements (GREs).

This transcriptional modulation affects the expression of target genes. Crucially, it promotes the transcription of proteins that inhibit the inflammatory cascade, such as Annexin A1 (Lipocortin-1). Annexin A1, in turn, acts as an inhibitor of Phospholipase A2 (PLA2). The suppression of PLA2 activity restricts the release of arachidonic acid from cell membrane phospholipids, which is the necessary precursor for the synthesis of pro-inflammatory eicosanoids, including prostaglandins and leukotrienes.

Concurrently, the GR-ligand complex directly or indirectly represses the activity of pro-inflammatory transcription factors, such as Nuclear Factor-kappa B (NF-κB), further reducing the synthesis of cytokines and chemokines. The systemic physiological consequence of these actions is local modulation of capillary permeability, vasoconstriction, and suppression of leukocyte migration at the site of administration.

Dosage and Administration Information

The administration of the Synalar rectal formulation is defined by instructions that specify the route, dosing schedule, and duration of therapy. This medication is designated for topical rectal administration and is supplied in two distinct dosage forms: a rectal ointment or cream, and a rectal suppository.

Official Administration Protocol

The standard regimen involves application once or twice daily. When utilizing the rectal ointment or cream, the typical dose is a measure equivalent to approximately 2 cm of cream, applied to the external area or inserted intra-rectally using a dedicated applicator. The suppository form is generally prescribed as one suppository per administration time.

Context and Duration

Proper use is dependent on timing and preparation. The instructions specify that the application should occur after a bowel movement (evacuation), with the affected anorectal area required to be thoroughly cleaned and dried prior to use.

This preparation is necessary to maintain consistency with the administration protocol. A critical limitation is that Synalar rectal is explicitly intended for short-term use only. The maximum continuous duration of treatment is limited to seven days, after which the patient’s clinical status must be re-evaluated if symptoms continue. Furthermore, the use of this medicine is restricted to Adults and Children over 12 years, as its safety and efficacy have not been established for use in younger pediatric patients.

Recent Clinical Evidence

Research Evidence / Overview of Studies

Combination Therapy (Fluocinolone Acetonide and Ketocaine)

Synalar rectal, containing the corticosteroid fluocinolone acetonide (FLA) often combined with the anesthetic ketocaine hydrochloride (KH), has been the subject of clinical research primarily focused on the conservative management of symptomatic hemorrhoidal disease (HD).

Study protocols mention the therapy's proposed interaction with inflammatory pathways and local vascular congestion. Research has investigated whether this combination influences the severity and duration of acute hemorrhoid symptoms, such as pain, itching, and inflammation, in adults.

Symptomology and Comparative Studies

Clinical trials examined endpoints related to changes in symptomatic scores, often including data collected within the initial 24 hours of administration. Studies compared the dual therapy against monotherapy (FLA or KH alone) to assess differences in reported symptom intensity over a defined treatment period.

Key Outcome Measures in Trials:

  • Changes in total clinical score (including nodule volume, pain, burning, and itching).
  • Patient-reported symptom severity and discomfort.
  • Changes in physical signs like edema and bleeding.

Safety and Study Populations

Research designs utilized in these studies typically included adult patients presenting with acute or exacerbated chronic hemorrhoids. Studies conducted to evaluate safety often reported that the combination was well-tolerated, with adverse events typically being mild and transient local reactions. Systemic absorption of the topical corticosteroid component is generally considered minimal, although it can be influenced by the extent of the treated area and mucosal integrity. Further research is ongoing, including studies designed to evaluate evidence across diverse patient groups.

Frequently Asked Questions (FAQ)

Common questions about Synalar rectal (FAQ)

Q: How is Synalar rectal different from other over-the-counter hemorrhoid creams?

A: Official product information describes Synalar rectal as a combination product containing both a high-potency corticosteroid (fluocinolone acetonide) and a local anesthetic (lidocaine). This comprehensive composition is a key feature that distinguishes it from many single-agent preparations often found over-the-counter.

Q: Is Synalar rectal only used for hemorrhoids?

A: According to the official product information, the common use of Synalar rectal is the symptomatic relief of anorectal disorders. While often used for hemorrhoidal disease, this description indicates a scope that may include other related conditions causing inflammation, pain, and itching.

Q: Can the cream interfere with the effectiveness of other medications I am taking orally?

A: Regulatory documents state that the active components in Synalar rectal can be systemically absorbed into the bloodstream. This means they have the potential to affect the clearance of other medicines taken orally, particularly those metabolized by specific liver enzymes. This highlights the caution noted in regulatory documents regarding co-administered medications.

Q: What is the purpose of the inactive ingredients in the Synalar rectal cream?

A: The purpose of inactive ingredients is generally to form the base of the cream or to preserve the medication. However, official product information also notes that these ingredients may, in some individuals, be a cause of localized skin irritation or allergic contact dermatitis.

Q: Can Synalar rectal be used safely during pregnancy?

A: Official labeling states that use during pregnancy is restricted. This medication should only be administered if the potential benefit justifies the potential risk to the fetus. This caution exists due to the potential for systemic absorption of the corticosteroid component.

Q: Is Synalar rectal safe to use while breastfeeding?

A: Caution is required for nursing mothers because official documents state that the systemic absorption of the active ingredients into breast milk is not fully established.

Q: Is there a higher risk of side effects for older patients using Synalar rectal?

A: One regulatory consideration notes that older patients (over 65 years) may be more likely to have skin changes that could increase the potential for side effects. This increased potential for side effects is why caution is noted in regulatory information for older patients.

Q: Does Synalar rectal have any known effect on blood sugar levels for people with diabetes?

A: Official labeling notes caution is required for patients with diabetes mellitus because the absorbed corticosteroid component may carry a documented risk of elevated blood glucose levels.

Q: Why is it important to tell the doctor about all other medications I am using?

A: The regulatory profile includes warnings regarding potential drug interactions due to effects on liver enzymes and risks of additive cardiac effects from the absorbed lidocaine component. The regulatory profile mandates this disclosure to screen for known risks.

Q: Does Synalar rectal treat the cause of hemorrhoids or just the symptoms?

A: Synalar rectal is explicitly described in its official purpose as providing symptomatic relief for the inflammation, pain, and itching associated with anorectal disorders. The product’s mechanism of action is focused on suppressing inflammation and providing local pain relief, rather than addressing the underlying cause of the condition.

Q: Is it safe to stop using the cream suddenly after using it for several days?

A: Official product information contains a caution regarding the abrupt discontinuation of treatment. This is because the sudden cessation of a corticosteroid treatment may lead to steroid withdrawal symptoms, such as rebound flares of dermatitis.

Q: Is it possible for Synalar rectal to cause serious side effects elsewhere in the body?

A: Yes. Serious safety considerations are related to the potential for systemic absorption of the steroid component. Officially documented risks include Hypothalamic-Pituitary-Adrenal (HPA) Axis Suppression (a form of adrenal suppression) and manifestations consistent with Cushing’s syndrome.

Q: What are the signs of too much medicine being absorbed?

A: Signs of possible systemic absorption, or hypercorticism, are described in regulatory sources. These symptoms may include blurred vision, dizziness, unusual tiredness and weakness, or increased thirst and urination.

Q: Can Synalar rectal be used on broken skin or open wounds?

A: Official warnings indicate that the systemic absorption of the steroid component can be increased when the product is used on damaged or broken skin. This increased absorption raises the chance of systemic side effects.

Q: What should be done if the cream accidentally gets into the eye?

A: Official regulatory guidance states that if the medication accidentally gets into the eye, rinsing with plenty of cool tap water is indicated.

Q: Can Synalar rectal weaken or damage latex products like condoms?

A: Official warnings state that this medication can damage and reduce the effectiveness of latex-containing products. This includes products such as condoms and diaphragms.

Q: Can I use Synalar rectal if I have an existing fungal infection in the area?

A: The product is formally restricted from use in the presence of an untreated local infection, which includes bacterial, viral, or fungal infections. The steroid component may obscure symptoms or exacerbate the underlying infection.

Q: What should I look out for to know if the cream is not working?

A: Official product guidance states that a re-evaluation of the patient’s clinical status is required if the condition does not show signs of improvement after the seven-day treatment limit.

Q: Can the use of Synalar rectal affect the results of future medical tests?

A: Official documentation mentions that lab tests may be ordered to monitor the body’s response, particularly if the product is used for an extended period. These tests may include those checking adrenal gland function.

Q: Are there specific storage requirements for Synalar rectal, such as temperature limits?

A: The official storage requirements mandate that the product be stored at controlled room temperature, between 15 C and 25 C (59 F and 77 F). It is also specified that the product must be protected from freezing.

Q: Is it true that Synalar rectal can cause changes in vision?

A: Changes in vision, such as blurred vision, are listed in official product information as potential symptoms. These symptoms should be reported, as they may be signs of systemic effects.

Q: Is Synalar rectal known to interact with herbal supplements?

A: Official patient safety information advises individuals to tell their healthcare provider about all herbal products and supplements being used. This disclosure is a regulatory caution necessary to assess the potential for interaction with other products.

Q: Is it normal to feel a mild burning or stinging sensation right after application?

A: Regulatory information states that side effects like burning, stinging, or irritation may occur when the medicine is first applied to the skin. If these effects occur, they should generally disappear within a few days.

Q: Can Synalar rectal affect the immune response in the local area?

A: The steroid component’s mechanism of action involves suppressing the inflammatory cascade. For this reason, official warnings restrict its use with untreated local infections because the steroid may obscure or exacerbate the infection.

How should Synalar rectal be stored and disposed of?

How to Store and Dispose of Synalar Rectal

The storage of Synalar rectal (fluocinolone acetonide rectal formulation) must strictly follow the conditions defined in the official regulatory labeling to ensure product stability.

Storage Requirements

Condition Requirement
Temperature Store at controlled room temperature, 15 C to 25 C (59 F to 77 F).
Handling Avoid freezing the product and protect it from excessive heat.
Protection Keep the medicine out of the sight and reach of children.

Disposal Instructions

Unused or expired Synalar rectal must be discarded according to official pharmaceutical waste guidelines. The product must not be disposed of through wastewater or household trash. Disposal should be done in accordance with local environmental requirements, often by returning the medicine to a pharmacy for regulated collection.

Attention! Always consult to a doctor or pharmacist before using pills or medicines.

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