Patients on Novolin should monitor their blood sugar closely, as an overdose of this drug will cause the blood sugar to drop dangerously low. The safety of using Novolin with pregnant or nursing pets has not been tested, so caution should be used. Pets taking anabolic steroids, beta adrenergic blockers, diuretics, estrogen agents, glucocorticoids, MAOIs, progestin, thyroid hormones, aspirin, digoxin, dobutamine, epinephrine, furosemide, phenylbutazone, or tetracycline should tell their vet before taking Novolin, as they may decrease its effectiveness.