What are tablets that dissolve under the tongue called?: A guide to sublingual medication

October 10, 2025 •

3 min read

Sublingual medications can start working significantly faster than traditional oral pills because they are absorbed directly into the bloodstream through the tissue under the tongue. This article explains what are tablets that dissolve under the tongue called and how this unique delivery method works to improve drug efficacy for specific conditions.

Quick Summary

An in-depth look at sublingual tablets, defining this specialized form of medication that dissolves under the tongue for rapid absorption directly into the bloodstream, bypassing the digestive system and liver.

Key Points

Sublingual is the term: Tablets that dissolve under the tongue are called sublingual tablets, from the Latin for 'under the tongue'.
Bypasses the liver: This route allows medications to enter the bloodstream directly, avoiding the first-pass metabolism in the liver and increasing bioavailability.
Rapid absorption: The thin, highly vascularized mucosa under the tongue ensures a quick onset of action for the medication.
Convenient for dysphagia: Sublingual tablets are an excellent alternative for patients who have difficulty swallowing traditional pills.
Requires proper technique: It is crucial to let the tablet dissolve completely under the tongue without chewing or swallowing it.
Not for all medications: Not every drug is suitable for sublingual administration, especially those that need a slow release or are required in large doses.
Distinct from buccal tablets: Buccal tablets are placed between the cheek and gum, whereas sublingual tablets go under the tongue.

What Exactly Are Sublingual Tablets?

Tablets that dissolve under the tongue are known as sublingual tablets, a term derived from Latin. This method of drug delivery involves placing substances under the tongue for absorption into the bloodstream through the oral mucosa. Unlike standard oral pills, sublingual tablets bypass the gastrointestinal tract and liver. This method is chosen when rapid action is necessary, as the area under the tongue is rich in blood vessels. Sublingual medications are also available as sprays, films, and drops.

How Do Sublingual Tablets Work?

When placed under the tongue, the tablet dissolves in saliva, releasing active ingredients that are absorbed through the mucosal membranes. This rapid absorption into the venous circulation bypasses the liver, which is a key benefit. Absorption under the tongue primarily involves passive diffusion, where drug molecules move from high to low concentration into the bloodstream. This process is beneficial as it avoids the liver's first-pass metabolism, potentially increasing drug concentration and potency in the bloodstream.

Key Advantages of Sublingual Administration

Sublingual administration offers several benefits over traditional oral tablets, including speed and patient convenience. It provides a rapid onset of action, crucial for urgent conditions like angina. Bypassing the liver can lead to higher bioavailability, potentially allowing for lower, more effective doses. Absorption is generally not affected by food or other oral medications. This method is also often easier for individuals with difficulty swallowing (dysphagia) and those who are unconscious or immobile.

How to Take Sublingual Tablets Correctly

Proper administration is essential for effectiveness. This typically involves sitting upright, placing the tablet under your tongue, and allowing it to dissolve completely without chewing or swallowing. It is recommended to avoid eating, drinking, or smoking until the tablet is fully dissolved. Ensuring your mouth is clean and moist beforehand can also help.

Common Examples of Sublingual Medications

Sublingual administration is used for various conditions requiring fast, direct absorption. Examples include Nitroglycerin for treating angina by dilating blood vessels, Buprenorphine for pain and opioid dependence, certain vitamins like B12 and D, and Zolpidem (Edluar) for insomnia.

Sublingual vs. Buccal vs. Oral Tablets

These oral medication types are differentiated by their placement and absorption sites.


Feature	Sublingual Tablets	Buccal Tablets	Traditional Oral Tablets
Placement	Under the tongue	Between the cheek and gum	Swallowed whole
Absorption Site	Oral mucosa, specifically under the tongue	Oral mucosa in the cheek	Primarily the small intestine
Speed of Absorption	Very rapid	Slower than sublingual	Slower onset
First-Pass Effect	Avoids first-pass metabolism	Avoids first-pass metabolism	Undergoes first-pass metabolism
Ideal Use	Urgent, rapid-action drugs	Sustained or slower absorption	Most common, standard route

Factors Influencing Sublingual Absorption

Several factors can impact how well sublingual medications are absorbed. These include the drug's properties, such as its solubility in both fat and water, which is important for crossing the mucous membrane. Saliva's pH and flow rate can influence absorption, and excessive saliva might lead to swallowing the drug. Oral health issues like sores, inflammation, or smoking can also affect absorption. The tablet formulation, specifically how quickly it dissolves, impacts drug release and absorption speed.

Conclusion

Sublingual tablets offer an effective drug delivery method by dissolving under the tongue. This route bypasses the digestive system and liver, leading to faster action and increased potency, which is beneficial in emergencies and for patients with swallowing difficulties. Understanding how they work and proper administration is vital for optimal treatment. Consult a healthcare provider for guidance. For more information on sublingual drug delivery, you can refer to {Link: neliti.com https://media.neliti.com/media/publications/409381-sublingual-drug-delivery-system-a-novel-694ef035.pdf} and {Link: NCBI https://www.ncbi.nlm.nih.gov/books/NBK568677/}.

Frequently Asked Questions

The term 'sublingual' is pronounced /ˌsʌbˈlɪŋ.ɡwəl/. You can break it down into three syllables: 'su-BLIN-gwuhl'.

Some tablets are designed to dissolve under the tongue to ensure a faster onset of action and a higher, more predictable concentration of the drug reaches the bloodstream. This is because the sublingual route bypasses the stomach and liver.

If you swallow a sublingual tablet, it will behave more like a traditional oral medication. It will likely take longer to work, and its effectiveness may be reduced due to exposure to stomach acid and first-pass metabolism in the liver.

The side effects of a sublingual tablet depend on the specific medication. For example, nitroglycerin may cause a burning or tingling sensation in the mouth. Some acidic drugs or fillers used in sublingual forms might cause tooth discoloration or decay with long-term use.

Sublingual tablets are designed for rapid absorption and can take effect much faster than traditional oral medications, often within minutes. The exact timing depends on the specific drug and formulation.

No, you should avoid eating, drinking, or smoking while a sublingual tablet is dissolving under your tongue. Doing so could wash the medication away before it has been fully absorbed, reducing its effectiveness.

While sublingual medication can be useful for children in some cases, patient cooperation is vital. It can be difficult for some children to keep the tablet under their tongue, so this route is not always suitable.