Understand oral hypoglycemic drugs and deal with missed doses scientifically

Author: Ni Huijun, Deputy Director Pharmacist, Qingdao Huangdao District Traditional Chinese Medicine Hospital

Reviewer: Hao Lipeng, deputy chief physician, Huangdao District Hospital of Traditional Chinese Medicine, Qingdao

Different hypoglycemic drugs have different mechanisms of action, which are closely related to the diet and lifestyle of diabetic patients. Therefore, if diabetic patients miss taking medication, they cannot simply make up for it. Wrong operation may even endanger their lives!

So, if you miss a dose of hypoglycemic drugs, should you make up for it? And how should you make up for it? To answer this question, we must first understand how hypoglycemic drugs work.

Figure 1 Copyright image, no permission to reprint

1. Mechanism of action of hypoglycemic drugs

Glucose-lowering drugs lower blood sugar levels through different mechanisms. One method is to lower blood sugar by increasing the amount of insulin, which has a greater blood sugar-lowering effect, but the risk of hypoglycemia also increases; another method is to increase the efficiency of insulin without increasing the amount of insulin, which is relatively mild, has a smaller blood sugar-lowering effect, and has a lower risk of hypoglycemia, so it is safer.

2. Commonly used oral hypoglycemic drugs and their characteristics

1. Sulfonylurea secretagogues (they often have the word "glimepiride" in their names, such as glimepiride, gliclazide, glipizide, etc.)

Features: As one of the earliest oral hypoglycemic drugs, sulfonylurea secretagogues are effective, inexpensive, and have no adverse effects on cardiovascular health or cancer risk. However, they can easily cause hypoglycemia and weight gain in patients.

2. Non-sulfonylurea secretagogues (often containing the word "glinide" in their names, such as repaglinide, nateglinide, etc.)

Features: Specially used to lower blood sugar after meals, convenient and flexible, but expensive and requires multiple doses. Improper use may cause hypoglycemia.

3. Biguanides (such as metformin)

Features: low price, significant effect, can reduce weight, protect cardiovascular system, good safety, will not cause hypoglycemia when used alone, and is the first choice for overweight or obese diabetic patients.

4. α-Glucosidase inhibitors (such as acarbose, voglibose, miglitol)

Features: It lowers blood sugar after a meal and needs to be chewed and swallowed at the same time as the first bite of staple food. It does not cause hypoglycemia when used alone, but it may cause hypoglycemia when used in combination with other hypoglycemic drugs, and once it occurs, glucose should be used for treatment.

5. Insulin sensitizers (thiazolidinediones, such as rosiglitazone, pioglitazone)

Features: Slow onset of effect, but more serious adverse reactions, such as edema and liver damage. Take the medicine at a fixed time every day.

6. Dipeptidyl peptidase IV (DPP-4) inhibitors (such as sitagliptin, saxagliptin, vildagliptin, etc.)

Features: It improves the blood sugar-lowering effect by prolonging the action time of the patient's own incretin hormones. It has good effects and few disadvantages, but the price is relatively high.

7. Sodium-glucose co-transporter 2 (SGLT-2) inhibitors (such as dapagliflozin, empagliflozin, etc.)

Features: It can reduce body weight, blood pressure, uric acid, improve blood lipids, and protect cardiovascular and kidney. Common adverse reactions include urinary and reproductive system infections, as well as adverse reactions related to hypovolemia; rare adverse reactions include diabetic ketoacidosis, etc. Drink as much water as possible during medication.

8. Glucokinase agonists (such as dopagliflozin)

Features: Glucokinase can keenly identify changes in blood sugar in the body to achieve blood sugar "steady state". The risk of hypoglycemia is low, and there is no need to adjust the dose when taking it for patients with kidney disease (those who have not yet undergone dialysis).

3. Two basic understandings of patients’ missed medications

1. Remind yourself to take medicine on time. For example, sulfonylurea secretagogues and non-sulfonylurea secretagogues need to be taken before meals. You can place the medicine on the dining table or in a conspicuous place as a reminder.

2. Do not make up for missed doses if you are not sure whether you need to make up for missed doses. If you are not sure whether you need to make up for missed doses, it is best not to make up for missed doses. At the same time, missed doses cannot be taken directly at double the dose the next time you take the medicine. Because improper make-up of hypoglycemic drugs may cause hypoglycemia, dizziness, fatigue, cold sweats and other symptoms, and in severe cases may even be life-threatening. Therefore, it is not recommended to make up for missed doses of hypoglycemic drugs unless under the guidance of a doctor.

4. How to deal with missed medications

To help people with diabetes better deal with missed medications, here are three checklists.

Figure 2 Copyright image, no permission to reprint

List 1: Do not take this type of medicine

α-Glucosidase inhibitors: These drugs need to be chewed and taken with the first bite of food during meals. Taking them after meals is less effective. If you miss a dose after a meal, you generally do not need to take it again.

List 2: These medicines can be taken at any time

(1) Biguanides: Since biguanides can be taken before, during or after meals, the time of taking them is relatively flexible, so if you miss a dose, you can take it immediately.

(2) Thiazolidinediones: This type of drug is not affected by meals and can be taken only once a day. If you miss a dose, you can take it immediately.

(3) DPP-4 inhibitors: This type of drug only needs to be taken once a day, and you can take it immediately if you miss a dose.

(4) SGLT-2 inhibitors: This type of drug is not affected by meals and is taken only once a day. If you miss a dose, you can take it immediately.

List 3: Take these medicines as needed

Sulfonylurea hypoglycemic drugs and non-sulfonylurea secretagogues: These drugs should be taken before meals. If you miss a dose during or just after a meal, you can make up for it with the original dose or a reduced dose, but you need to prevent hypoglycemia before the next meal. If necessary, you can add an appropriate meal before the next meal. If you miss a dose too long after a meal, do not make up for it. Because blood sugar will increase as food is digested after eating, taking hypoglycemic drugs at this time will not only have no blood sugar lowering effect, but will increase the risk of hypoglycemia.

References

[1] Yang Ling. Learn to choose hypoglycemic drugs[J]. Family Medicine. Happy Health, 2023, (7): 44.

[2] Hua Yafang, Liu Xiaomin. SGLT2i: Research progress on cardiovascular and renal protective effects in diabetes[J]. Journal of Cardiovascular Rehabilitation Medicine, 2023, 32(3): 312-315.

[3] Lin Yuxing, Feng Shuling. Correctly grasp the “time window” for taking oral hypoglycemic drugs [J]. Strait Pharmacy, 2009, 21(8): 156-157.