Diltiazem cream is a topical medication used primarily to treat anal fissures, those small but intensely painful tears in the lining of the anal canal. Applied directly to the affected area, typically at a concentration of 2%, it works by relaxing the internal anal sphincter muscle, which reduces spasm, restores blood flow, and allows the fissure to heal. Because there is no commercially manufactured topical version in most countries, the cream is almost always made by a compounding pharmacy, and that introduces some practical wrinkles worth understanding.
How Diltiazem Cream Works
Anal fissures persist largely because of a vicious cycle: the tear causes pain, the pain triggers spasm in the internal anal sphincter, the spasm cuts off blood supply to the wound, and poor blood supply prevents healing. Diltiazem belongs to a class of drugs called calcium channel blockers. When applied topically, it blocks calcium from entering smooth muscle cells in the sphincter, which interrupts the spasm and lets the muscle relax.1PubMed Central. The efficacy of diltiazem, glyceryl trinitrate, nifedipine, minoxidil, and lidocaine for the medical management of anal fissure: a systematic review and network meta-analysis of randomized controlled trials With the sphincter relaxed, blood flow improves and the tissue can begin to repair itself. This is sometimes called “chemical sphincterotomy” because it achieves something functionally similar to a surgical cut of the sphincter, but without any permanent structural change to the muscle.
How Well Does It Heal Fissures?
Healing rates in studies vary depending on how long patients use the cream and whether fissures are acute or chronic, but the numbers are generally encouraging as a first-line treatment. In one study of 68 patients using topical diltiazem, about three-quarters healed after two to three months. Among those who did not heal initially, an additional eight weeks of treatment brought most of them around, so that the vast majority ultimately healed on diltiazem alone.2PubMed Central. Topical diltiazem ointment in the treatment of chronic anal fissure Another trial comparing topical diltiazem against oral diltiazem found that the cream outperformed the pill, with about two-thirds of patients in the topical group achieving complete healing by eight weeks compared to roughly a third in the oral group.3PubMed. A randomized trial of oral vs. topical diltiazem for chronic anal fissures
Beyond just closing the wound, treatment improves daily life in measurable ways. Patients who healed on diltiazem reported significant reductions in pain, bleeding, and irritation, along with improvements in physical functioning and overall vitality on standardized quality-of-life measures.4PubMed. Quality of life in patients with chronic anal fissure That matters because chronic anal fissures are not just physically painful; they can dominate a person’s daily routine, making every trip to the bathroom something to dread.
Diltiazem Versus Nitroglycerin Ointment
Glyceryl trinitrate, commonly called nitroglycerin or GTN, is the other major topical option for anal fissures. It relaxes the sphincter through a different pathway, releasing nitric oxide. The natural question is which one works better, and the evidence is consistent: they heal fissures at about the same rate. A meta-analysis pooling nine randomized trials found no meaningful difference in healing between the two.5PubMed Central. Topical diltiazem and glyceryl-trinitrate for chronic anal fissure: A meta-analysis of randomised controlled trials Individual trials echo the same finding, with healing rates in the range of 76% to 86% for GTN and 80% to 86% for diltiazem, and no statistically significant gap between them.6Colorectal Disease. A prospective randomized trial of diltiazem and glyceryltrinitrate ointment in the treatment of chronic anal fissure
Where diltiazem pulls ahead is side effects, particularly headaches. GTN causes headaches in a substantial fraction of users, sometimes severe enough to stop treatment. In one head-to-head trial, almost half the GTN group reported headaches compared to about 14% of the diltiazem group.7International Surgery Journal. Topical diltiazem versus topical glyceryl trinitrate in the treatment of chronic anal fissure: a prospective comparative study Another trial recorded headache and dizziness in a third of GTN patients, while no patients using diltiazem reported any side effects at all.8Colorectal Disease. A prospective randomized trial of diltiazem and glyceryltrinitrate ointment in the treatment of chronic anal fissure This tolerability advantage is a major reason diltiazem has become the preferred first-line topical treatment in many clinical settings.
Diltiazem Versus Surgery
Lateral internal sphincterotomy, a minor surgical procedure that makes a small cut in the internal sphincter, is considered the gold standard for chronic anal fissures that fail medical treatment. Surgery heals fissures at very high rates, often above 90%. Compared to surgery, diltiazem heals fewer fissures overall, particularly long-standing ones. In a randomized trial, the surgical group achieved a 94% healing rate compared to 65% with a combination of botulinum toxin and diltiazem. However, among patients whose fissures had been present for a year or less, both groups hit 100% healing.9PubMed. Partial lateral internal sphincterotomy versus combined botulinum toxin A injection and topical diltiazem in the treatment of chronic anal fissure: a randomized clinical trial That distinction is important: the longer a fissure has been entrenched, the less likely medical treatment alone will resolve it.
The trade-off, though, is risk. Surgery carries a real chance of permanent damage to continence. One study found that 30% of patients who had lateral sphincterotomy experienced flatus incontinence at six months, compared to only 2% in the diltiazem group.10PubMed Central. A Comparative Study of Topical 2% Diltiazem Versus Lateral Internal Sphincterotomy in the Treatment of Fissure-in-Ano Another trial recorded fecal incontinence in over 13% and flatus incontinence in 20% of surgery patients, with zero incontinence in the diltiazem group.11International Surgery Journal. Efficacy of chemical sphincterotomy with 2% diltiazem cream vs. surgical sphincterotomy in the management of chronic fissure in ano: a clinical study Incontinence rates vary across studies, and some surgical series report much lower numbers, but the risk is inherent to cutting a sphincter muscle. Diltiazem leaves the sphincter structurally intact, so any change in pressure is temporary and fully reversible once you stop applying the cream. This makes it a sensible first step before considering surgery.
Side Effects You Might Actually Experience
Topical diltiazem is well tolerated overall, especially compared to GTN. The most commonly reported side effect is perianal itching, which showed up in about 15% of patients in one trial.12Annals of Surgery. Topical Diltiazem Cream Versus Botulinum Toxin A for the Treatment of Chronic Anal Fissure Most patients who experience itching continue using the cream without problems. In a quality-of-life study, four out of 48 patients developed perianal itching and one reported headache, but all were mild.13PubMed Central. Quality of life in patients with chronic anal fissure after topical treatment with diltiazem More serious reactions are rare; one study noted a single patient who developed headaches, drowsiness, and mood changes after six weeks of use and discontinued the treatment.14PubMed. Diltiazem heals glyceryl trinitrate-resistant chronic anal fissures: a prospective study
Because the cream is applied locally and in a small amount, systemic absorption is minimal compared to oral diltiazem tablets (which are used for heart conditions and high blood pressure). This is why side effects like dizziness, low blood pressure, or heart-rhythm changes, all familiar with oral diltiazem, are essentially absent with the topical form. That said, if you are already taking oral calcium channel blockers or other blood pressure medications, mention it to whoever prescribes the cream, just to be cautious.
The Recurrence Problem
The honest weak spot in diltiazem treatment is recurrence. The cream can heal the fissure, but it does not fix whatever caused the fissure in the first place, which is usually some combination of hard stools, straining, and chronically elevated sphincter tone. In one long-term follow-up study, about 59% of patients needed further treatment, either additional medical therapy or eventually surgery, over an average two-year follow-up period.15PubMed. The long-term results of diltiazem treatment for anal fissure A trial tracking patients over six months found a recurrence rate of about 21% in the diltiazem group.16PubMed Central. The Effect of Topical Nifedipine versus Diltiazem on the Acute Anal Fissure: A Randomized Clinical Trial
Recurrence does not mean the treatment was useless. Many patients who relapse respond to a second course of topical treatment. And for some people, a recurrence is the point at which surgery becomes the more reasonable choice, especially if the fissure has been coming and going for over a year. The general strategy is to try medical therapy first, recognize that it may take more than one round, and reserve surgery for cases that genuinely do not respond.
Combining Diltiazem with Botulinum Toxin
Botulinum toxin (Botox) injections into the anal sphincter are another option for fissures that resist topical therapy. The idea of combining botulinum toxin with diltiazem cream sounds logical on paper: the injection provides a strong, sustained relaxation of the sphincter, and the cream maintains that effect between injections. In practice, the evidence is mixed. A randomized trial found no significant benefit to adding diltiazem cream on top of botulinum toxin injections, with healing rates of roughly 37% in the combination group versus 31% with botulinum toxin alone on an intention-to-treat basis.17Diseases of the Colon & Rectum. Botulinum Toxin Injection Plus Topical Diltiazem for Chronic Anal Fissure: A Randomized Double-Blind Clinical Trial and Long-term Outcome A retrospective study with longer follow-up confirmed this, finding no significant difference in healing or recurrence rates when diltiazem was added to botulinum toxin.18PubMed Central. Retrospective analysis on the efficacy of botulinum toxin alone versus combined botulinum toxin and topical diltiazem
The combination approach may still have a role in selected patients, particularly those with fissures that are chronic but less than a year old, where one trial showed very high combined healing rates.19PubMed. Partial lateral internal sphincterotomy versus combined botulinum toxin A injection and topical diltiazem in the treatment of chronic anal fissure: a randomized clinical trial But as a blanket strategy, adding diltiazem to botulinum toxin does not appear to improve outcomes enough to justify the added cost and inconvenience for most patients.
Compounding Quality Is Not Guaranteed
Because topical diltiazem is not manufactured by a pharmaceutical company, you get it from a compounding pharmacy, which mixes it on-site from raw ingredients. The quality of compounded medications varies more than most patients realize. A study tested 36 compounded diltiazem preparations and found that about half fell outside acceptable potency standards: roughly 14% were too strong and 36% were too weak, with some containing barely a third of the labeled amount of diltiazem.20PubMed Central. Quality of compounded topical 2% diltiazem hydrochloride formulations for anal fissure Nearly 39% of the preparations also failed content uniformity testing, meaning the concentration of diltiazem was not consistent throughout the jar or tube.
This is not a reason to avoid the cream, but it is a reason to use a reputable compounding pharmacy and to ask questions. A pharmacy that tests its finished products for potency is a step above one that mixes and ships without verification. If you have been using diltiazem cream diligently and your fissure has not improved after eight weeks, it is worth considering whether the preparation itself might be subpotent before concluding that the medication does not work for you.
How to Store It
Storage matters more than you might expect for a compounded product. Stability research shows that diltiazem cream (in a standard cream base) is stable for at least 30 days at room temperature or in the refrigerator, but degrades rapidly in heat. If the cream is exposed to elevated temperatures, such as being left in a car in summer, it may lose potency within days. Gel formulations are more robust, remaining stable for up to 90 days at room temperature or refrigerator conditions. Ointment formulations in a petrolatum base are also stable for about 90 days at room temperature but should not be refrigerated, as cold causes physical changes in the base.21International Journal of Pharmaceutical Compounding. Stability of Compounded Diltiazem Hydrochloride in Cream, Ointment, and Gel Formulations for Topical Use
The practical takeaway: keep your diltiazem at room temperature, out of direct heat, and use it within the expiration date the pharmacy provides. If you receive it in cream form and your pharmacy gives a 30-day beyond-use date, do not try to stretch it further. If you need a longer shelf life, ask whether a gel or ointment formulation is available.
Use in Children
Anal fissures are common in young children, often triggered by constipation. The same topical diltiazem used in adults has been studied in pediatric populations and appears to be both safe and effective. A randomized trial in children comparing diltiazem, GTN, and lidocaine found diltiazem effective with a low recurrence rate and minimal side effects.22PubMed. A prospective, randomized, double-blind study comparing the efficacy of diltiazem, glyceryl trinitrate, and lidocaine for the treatment of anal fissure in children A larger trial in pediatric patients found that a combination of diltiazem and lignocaine (a local anesthetic) healed about 83% of acute fissures by six weeks, significantly outperforming the GTN-and-lignocaine combination, which healed about 64%.23Proceedings S.Z.M.C. Topical Lignocaine with Diltiazem or Glyceryltrinitrate for Paediatric Acute Anal Fissure: A Randomized Clinical Trial The advantage of diltiazem over GTN in children is the same as in adults: similar or better healing with far fewer headaches and other side effects, which is especially important because small children cannot articulate symptoms like headache clearly.
Pregnancy and Anal Fissures
Anal fissures are common during pregnancy and in the postpartum period, driven by constipation and the physical stress of delivery. Treating them is tricky because many medications raise safety concerns during pregnancy. Diltiazem cream is generally considered the safer topical option compared to nitroglycerin for pregnant patients, partly because nitroglycerin can cause severe headaches and is more likely to lower blood pressure systemically.24Visceral Medicine. Incidence, Diagnosis, and Management of Proctological Conditions during Pregnancy That said, formal safety data on topical diltiazem in pregnancy is limited, so the decision should involve a conversation with your obstetrician. The low systemic absorption of the topical form is reassuring, but no large controlled trials have been conducted specifically in pregnant women.
Cost and Access
One underappreciated advantage of diltiazem cream is cost. Because it is a compounded topical medication rather than a branded pharmaceutical product, it is relatively inexpensive compared to surgery or repeated botulinum toxin injections. Conservative treatments for anal fissures generally cost far less than surgical interventions.25PubMed. Cost considerations in the treatment of anal fissures However, compounded medications are not always covered by insurance, and coverage varies widely by plan and country. In some healthcare systems, you may need a prescription specifically written for a compounding pharmacy, and the out-of-pocket cost can range from modest to moderately annoying depending on your location. It is worth calling the pharmacy ahead to confirm price and turnaround time, since compounded products are made to order and may take a day or two to prepare.
Access can also be an issue in rural areas where compounding pharmacies are scarce. Some compounding pharmacies ship refrigerated medications by mail, which solves the access problem but requires attention to the storage considerations discussed earlier, particularly in warm climates.