Is dibucaine ointment better than Preparation H?

October 8, 2025 •

4 min read

Affecting about 1 in 20 Americans, hemorrhoids are a common condition causing significant discomfort [1.7.6]. When seeking relief, many wonder: is dibucaine ointment better than Preparation H? The answer depends on the primary symptoms you need to address, as they work in fundamentally different ways.

Quick Summary

Dibucaine ointment is a potent topical anesthetic that numbs pain and itching. Preparation H primarily uses a vasoconstrictor to shrink swollen hemorrhoidal tissue. The better choice depends on whether pain or swelling is the main issue.

Key Points

Different Mechanisms: Dibucaine is a topical anesthetic that numbs pain and itching by blocking nerve signals [1.3.1].
Swelling vs. Pain: Preparation H contains phenylephrine, a vasoconstrictor that shrinks swollen hemorrhoid tissue [1.4.1].
Symptom-Based Choice: Choose dibucaine for severe pain relief; choose Preparation H for reducing swelling [1.2.1, 1.3.2].
Combination Products: For both pain and swelling, look for Preparation H formulations that include an anesthetic like pramoxine [1.4.3].
Safety First: Do not use these products for more than 7 days without consulting a doctor [1.3.4, 1.4.6].
Medical Consultation: People with high blood pressure, heart disease, or other chronic conditions should consult a doctor before using products with phenylephrine [1.4.7].
Not a Cure: These treatments manage symptoms; they do not cure the underlying cause of hemorrhoids.

Understanding Hemorrhoids and Treatment Goals

Hemorrhoids are swollen veins in the lower rectum and anus, similar to varicose veins. They can be internal (inside the rectum) or external (under the skin around the anus) [1.7.6]. Symptoms often include pain, itching, bleeding, and swelling [1.7.3]. The fourth leading outpatient gastrointestinal diagnosis in the U.S., hemorrhoids affect a significant portion of the population, with prevalence peaking between ages 45 and 65 [1.7.2]. Over-the-counter (OTC) treatments are typically the first line of defense, aiming to manage these uncomfortable symptoms. Two common, yet distinct, options are dibucaine ointment and the various formulations of Preparation H.

What is Dibucaine Ointment?

Dibucaine is a powerful topical local anesthetic [1.3.8]. Its primary brand name is Nupercainal [1.3.1]. As an anesthetic, its sole function is to provide temporary relief from pain and itching by blocking nerve signals in the skin [1.3.2, 1.3.5]. It works by stabilizing the neuronal membrane and preventing the transmission of pain impulses to the brain [1.3.1].

Mechanism of Action: Dibucaine belongs to the amide class of local anesthetics and is one of the most potent and long-acting available [1.3.8, 1.6.1]. It blocks sodium channels in nerve endings, which inhibits depolarization and stops the nerve from sending a pain signal [1.3.1]. The numbing effect typically begins within 15 minutes and can last for 2 to 4 hours [1.3.1]. It is important to note that dibucaine treats the symptom of pain; it does not reduce the underlying swelling of the hemorrhoid tissue itself [1.2.1].

What is Preparation H?

Preparation H is a brand name that encompasses a wide range of products for hemorrhoid treatment [1.4.5]. While formulations vary, the most common active ingredient in products like Preparation H Ointment is phenylephrine, a vasoconstrictor [1.4.2, 1.4.7]. Some formulations, such as Preparation H Maximum Strength Pain Relief Cream, also include a local anesthetic like pramoxine [1.2.2, 1.4.3].

Mechanism of Action:

Phenylephrine: This drug works by narrowing, or constricting, the blood vessels in the applied area [1.4.1, 1.4.8]. Since hemorrhoids are swollen blood vessels, constricting them temporarily reduces their size, thus relieving swelling, and the discomfort and itching associated with it [1.2.4, 1.4.1].
Pramoxine: Found in certain Preparation H products, pramoxine is a topical anesthetic that relieves pain and itching by numbing the area [1.4.3, 1.6.1].
Protectants: Many Preparation H products also contain protectants like mineral oil, petrolatum, or shark liver oil, which form a soothing, protective barrier over the irritated tissue to prevent further irritation from stool [1.4.1, 1.4.7].

Unlike dibucaine which only numbs, Preparation H with phenylephrine actively works to shrink the swollen tissue [1.2.1, 1.2.4].

Head-to-Head Comparison: Dibucaine vs. Preparation H

The fundamental difference lies in their primary function: pain-blocking versus tissue-shrinking. The choice between them is not about one being universally "better," but which one is better suited for your specific symptoms.


Feature	Dibucaine Ointment (Nupercainal)	Preparation H (Phenylephrine-based)
Primary Function	Pain and itch relief (Anesthetic) [1.3.2]	Reduces swelling (Vasoconstrictor) [1.4.1]
Mechanism	Blocks nerve signals by inhibiting sodium channels [1.3.1].	Narrows swollen blood vessels [1.4.1, 1.4.8].
Addresses Swelling?	No [1.2.1].	Yes, this is its main purpose [1.2.4].
Addresses Pain?	Yes, this is its main purpose [1.3.5].	Only in formulations containing an anesthetic like pramoxine [1.4.3].
Active Ingredient	Dibucaine 1% [1.3.3].	Phenylephrine HCl 0.25% (often with protectants) [1.4.7].
Common Use Case	Best for severe pain and itching.	Best for swollen, uncomfortable hemorrhoids.
Potential Side Effects	Skin irritation, burning, photosensitivity [1.2.3, 1.3.4].	Rectal irritation. Potential for increased blood pressure with systemic absorption [1.2.3, 1.4.6].

Which Ointment Should You Choose?

Deciding between dibucaine and Preparation H depends on your most prominent symptom.

Choose Dibucaine if your primary complaint is severe pain or itching. If the discomfort and pain are the most bothersome aspects of your hemorrhoids, a potent anesthetic like dibucaine will provide the most direct and powerful numbing relief [1.3.2, 1.3.5].
Choose Preparation H (with phenylephrine) if your primary complaint is swelling and physical discomfort. If you are more troubled by the size and inflammation of the hemorrhoids, the vasoconstrictor action of phenylephrine is designed specifically to address this issue by shrinking the tissue [1.2.4, 1.4.1].
Consider a Combination Product for Multiple Symptoms. For those experiencing both significant pain and swelling, a product like Preparation H Maximum Strength Pain Relief Cream can be an excellent option. It combines a vasoconstrictor (phenylephrine) to reduce swelling with an anesthetic (pramoxine) to numb the pain, offering a multi-symptom approach [1.2.2, 1.4.3].

Important Precautions and When to See a Doctor

While both medications are available over-the-counter, they are not without risks. Always follow the product's directions.

Dibucaine: For external use only. Do not use on large areas of skin, broken or blistered skin, or for more than 7 days unless directed by a doctor [1.3.1, 1.3.4]. Overuse can lead to systemic absorption and more serious side effects [1.3.1].
Preparation H (Phenylephrine): Individuals with heart disease, high blood pressure, thyroid disease, or diabetes should consult a doctor before using products containing phenylephrine, as it can be absorbed into the bloodstream and affect blood pressure [1.4.6, 1.4.7].

If your symptoms do not improve within 7 days, if bleeding occurs, or if your condition worsens, stop use and consult a healthcare provider [1.3.4, 1.4.6]. These could be signs of a more serious condition.

Conclusion

To answer the question, is dibucaine ointment better than Preparation H? — neither is objectively superior. They are different tools for different jobs. Dibucaine is a specialist in numbing severe pain, while Preparation H specializes in shrinking swollen tissue. The best choice is the one that targets the symptom causing you the most distress. For comprehensive relief from both pain and swelling, a combination product may be the most effective solution.

For more information on treatment options, you can visit the Mayo Clinic's page on hemorrhoids: https://www.mayoclinic.org/diseases-conditions/hemorrhoids/diagnosis-treatment/drc-20360280 [1.5.7]

Frequently Asked Questions

The main difference is their mechanism of action. Dibucaine is a local anesthetic that numbs pain and itching, while the primary ingredient in most Preparation H products, phenylephrine, is a vasoconstrictor that shrinks swollen hemorrhoid tissue [1.2.1, 1.2.4].

Dibucaine ointment is generally better for severe, direct pain relief because it is a potent topical anesthetic specifically designed to block pain signals [1.3.2, 1.3.5]. Some Preparation H versions also contain an anesthetic (pramoxine) for pain relief [1.2.2].

Preparation H containing phenylephrine is designed to reduce swelling. Phenylephrine works by narrowing the blood vessels, which temporarily shrinks the hemorrhoidal tissue [1.4.1].

You should consult a healthcare provider before combining medications. Alternatively, you could use a single product, like Preparation H Maximum Strength Pain Relief, which contains both a vasoconstrictor (phenylephrine) and an anesthetic (pramoxine) to treat both swelling and pain [1.4.3].

Dibucaine typically begins to work within 15 minutes of application, and its anesthetic effects can last for 2 to 4 hours [1.3.1].

You should consult your doctor before using Preparation H if you have high blood pressure. Its active ingredient, phenylephrine, can be absorbed and potentially raise blood pressure [1.4.6, 1.4.7].

You should not use over-the-counter hemorrhoid treatments like dibucaine or Preparation H for more than 7 days unless directed by a doctor. If symptoms persist or worsen, seek medical advice [1.3.4, 1.4.6].