DESCRIPTION
Nizatidine USP is a histamine H2-receptor antagonist. Chemically, it is N-[2-[[[2-[(Dimethylamino)methyl]-4-thiazolyl]methyl]thio]ethyl]-N'-methyl-2-nitro-1,1-ethenediamine. The structural formula is represented below:
It is an off-white to buff crystalline solid that is soluble in water. Nizatidine has a bitter taste and mild sulfur-like odor. Nizatidine Capsules USP, for oral administration, contain 150 mg or 300 mg nizatidine and the following inactive ingredients: colloidal silicon dioxide, corn starch, croscarmellose sodium, magnesium stearate and pregelatinized starch. The capsule shells contain: ammonium hydroxide, black iron oxide, gelatin, potassium hydroxide, propylene glycol, shellac, silicon dioxide, sodium lauryl sulfate and titanium dioxide.
The 150 mg capsule shell also contains D&C Yellow No. 10 and FD&C Yellow No. 6.
The 300 mg capsule shell also contains black iron oxide, red iron oxide and yellow iron oxide.
CLINICAL PHARMACOLOGY
Nizatidine is a competitive, reversible inhibitor of histamine at the histamine H2-receptors, particularly those in the gastric parietal cells.
Antisecretory Activity
-
Effects on Acid Secretion: Nizatidine significantly inhibited nocturnal gastric acid secretion for up to 12 hours. Nizatidine also significantly inhibited gastric acid secretion stimulated by food, caffeine, betazole, and pentagastrin (Table 1).
Table 1. – Effect of Oral Nizatidine on Gastric Acid Secretion
|
|
Time After |
% Inhibition of Gastric Acid |
|
|
Dose (h) |
Output by Dose (mg) |
|
|
|
20-50 |
75 |
100 |
150 |
300 |
|
Nocturnal |
Up to 10 |
57 |
|
73 |
|
90 |
|
Betazole |
Up to 3 |
|
93 |
|
100 |
99 |
