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Routes of Drug Administration: Enteral
Medications can be administered through the enteral route using liquids, capsules, or tablets.
Enteral administration involves drug administration via…
Drugs administered through the enteral route can be liquid or in the form of capsules or tablets. Administration by mouth can be oral or sublingual.
Oral drugs pass through the GI tract and are metabolized by the liver. Then they are absorbed into the systemic circulation.
While passing through the stomach, certain drugs may be destroyed by gastric secretions, or they may cause gastric irritation.
For such drugs, enteric coating is used, which protects the drug from stomach acid and dissolves it in the less acidic intestine.
Controlled-release preparations can facilitate slow and uniform absorption of drugs.
The longer duration of action is useful for drugs with short half-lives as it reduces the frequency of administration. The formulation also reduces undesired effects.
For drugs that are unstable in gastric secretions or get rapidly metabolized by the liver, the sublingual route proves beneficial, wherein the drug diffuses into the capillary network under the tongue and is directly absorbed into the systemic circulation, bypassing the GI tract and hepatic metabolism.
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Q1: What are the different forms of enteral drug administration?
Enteral drugs can be administered as liquids, capsules, or tablets through two routes: oral or sublingual. Oral administration involves swallowing the drug, which passes through the gastrointestinal tract and is metabolized by the liver before entering systemic circulation. Sublingual administration places the drug under the tongue, where it diffuses directly into capillaries and bypasses the GI tract and hepatic metabolism for faster absorption.
Q2: Why do some oral drugs require enteric coating?
Certain drugs are vulnerable to destruction by gastric secretions or cause gastric irritation when passing through the stomach. Enteric coating protects these sensitive drugs from stomach acid and only dissolves in the less acidic intestinal environment, allowing safe absorption without damage or side effects.
Q3: How do controlled-release preparations improve drug delivery?
Controlled-release formulations are engineered to release drugs slowly and uniformly over an extended period, promoting consistent absorption. This prolonged action is particularly beneficial for drugs with short half-lives, as it reduces the frequency of dosing and minimizes undesired side effects while maintaining therapeutic effectiveness.
Q4: What is the advantage of sublingual drug administration?
The sublingual route is advantageous for drugs unstable in gastric secretions or rapidly metabolized by the liver. The drug diffuses into the capillary network beneath the tongue and is directly absorbed into systemic circulation, bypassing the GI tract and liver metabolism for more effective medication delivery to the body.
Q5: How does oral drug metabolism differ from sublingual absorption?
Oral drugs pass through the gastrointestinal tract and are metabolized by the liver before entering systemic circulation, which can reduce drug effectiveness. Sublingual drugs bypass both the GI tract and hepatic metabolism, allowing direct absorption into systemic circulation and preserving the drug's potency for conditions requiring rapid or more efficient delivery.
Q6: What happens to drugs during oral administration through the stomach?
While passing through the stomach, certain drugs may be destroyed by gastric secretions or cause gastric irritation. These challenges are addressed through enteric coating, which shields the drug from stomach acid, or by using the sublingual route to avoid gastric exposure entirely and ensure safe, effective drug delivery.
Q7: How does enteral administration compare to other routes of drug administration?
Enteral administration through the mouth offers convenient, non-invasive drug delivery via oral or sublingual routes. While oral drugs undergo hepatic metabolism and GI tract exposure, sublingual drugs bypass these processes. Understanding enteral administration helps contextualize additional routes of drug administration and factors affecting drug response in pharmacological treatment.