Precautions and Warnings With NPH Insulin
It is important to talk to your healthcare provider about the precautions and warnings with NPH insulin, even though the drug is available without a prescription. If you have kidney or liver problems, it may affect your insulin dosage. You should not use NPH insulin if you do not have diabetes or do not have your healthcare provider's approval to take the medication.
Talk with your healthcare provider prior to taking NPH insulin (Humulin® N, Novolin® N) if you have:
- Liver disease, such as cirrhosis, liver failure, or hepatitis
- Kidney disease, such as kidney failure (renal failure)
- Any allergies, including allergies to foods, dyes, or preservatives.
Also, let your healthcare provider know if you are:
- Pregnant or thinking of becoming pregnant.
Make sure to tell your healthcare provider about any medications you are taking, including prescription and non-prescription medicines, vitamins, and herbal supplements.
Warnings and precautions to be aware of prior to taking NPH insulin include the following:
- Even though NPH insulin is available without a prescription, it should be used only with your healthcare provider's approval and supervision. Using this medication inappropriately can be lethal.
- Low blood sugar (hypoglycemia) is the most common (and usually most serious) side effect of insulin medications, including NPH insulin. Make sure you and those around you know how to identify the warning signs for low blood sugar and how to respond. You must test your blood sugar levels regularly while taking NPH insulin or any other insulin. Low blood sugar levels can be a life-threatening problem.
- Illness and changes in diet, exercise, or other medications, and overall health can affect how much NPH insulin you need. Make sure your healthcare provider explains how and when you should make any NPH insulin dosage adjustments.
- Liver and kidney problems may affect your NPH insulin dosage. Also, changes in diet or exercise, illness, or stress may affect your blood sugar levels in such a way that your dosage needs to be adjusted.
- This diabetes medication can potentially interact with several other medications (see Drug Interactions With NPH Insulin).
- Make sure your healthcare provider shows you exactly how to inject NPH insulin, how to store the drug, and how to dispose of your used needles.
- NPH insulin is considered a pregnancy Category B medication. This means it is most likely safe for use during pregnancy, although the full risks are not known (see Novolin N and Pregnancy or Humulin N and Pregnancy).
- It is not known if NPH insulin passes through breast milk. Therefore, if you are breastfeeding or plan to start, discuss this with your healthcare provider prior to taking the drug (see Novolin N and Breastfeeding or Humulin N and Breastfeeding).