DOSAGE AND ADMINISTRATION
Adult: The usual adult, oral dosage is 2 to 3 tablespoonfuls (30 to
45 mL, containing 20 g to 30 g of lactulose) three or four times daily. The
dosage may be adjusted every day or two to produce 2 or 3 soft stools daily.
Hourly doses of 30 to 45 mL of lactulose solution may be used to induce the
rapid laxation indicated in the initial phase of the therapy of portal-systemic
encephalopathy. When the laxative effect has been achieved, the dose of lactulose
may then be reduced to the recommended daily dose. Improvement in the patient's
condition may occur within 24 hours but may not begin before 48 hours or even
Continuous long-term therapy is indicated to lessen the severity and prevent
the recurrence of portal-systemic encephalopathy. The dose of lactulose for
this purpose is the same as the recommended daily dose.
Pediatric: Very little information on the use of lactulose in young
children and adolescents has been recorded. As with adults, the subjective goal
in proper treatment is to produce 2 or 3 soft stools daily. On the basis of
information available, the recommended initial daily oral dose in infants is
2.5 to 10 mL in divided doses. For older children and adolescents, the total
daily dose is 40 to 90 mL. If the initial dose causes diarrhea, the dose should
be reduced immediately. If diarrhea persists, lactulose should be discontinued.
When the adult patient is in the impending coma or coma stage of portal- systemic
encephalopathy and the danger of aspiration exists, or when the necessary endoscopic
or intubation procedures physically interfere with the administration of the
recommended oral doses, lactulose solution may be given as a retention enema
via a rectal balloon catheter. Cleansing enemas containing soap suds or other
alkaline agents should not be used.
Three hundred mL of lactulose solution should be mixed with 700 mL of water
or physiologic saline and retained for 30 to 60 minutes. Lactulose enema may
be repeated every 4 to 6 hours. If this lactulose enema is inadvertently evacuated
too promptly, it may be repeated immediately.
The goal of treatment is reversal of the coma stage in order that the patient
may be able to take oral medication. Reversal of coma may take place within
2 hours of the first enema in some patients. Lactulose given orally in the recommended
doses, should be started before lactulose by enema is stopped entirely.
Lactulose Solution USP (Oral or Rectal Solution), 10 g/15 mL, is a clear, yellow
to golden-yellow solution supplied in one pint (473 mL) and two quart (1.89
L) bottles. Lactulose solution contains: 667 mg lactulose/mL (10 g/15 mL).
Store at 25° C (77° F); excursions permitted to 15-30°C (59-86°F) (see USP
Controlled Room Temperature). Do not freeze. Keep tightly closed.
Under recommended storage conditions, a normal darkening of color may occur.
Such darkening is characteristic of sugar solutions and does not affect therapeutic
Prolonged exposure to temperatures above 86° F (30° C) or to direct light may
cause extreme darkening and turbidity which may be pharmaceutically objectionable.
If this condition develops, do not use. Prolonged exposure to freezing temperatures
may cause change to a semisolid, too viscous to pour. Viscosity will return
to normal upon warming to room temperature.
Dispense in a tight, light-resistant container as defined in the USP, with
a child-resistant closure.
Manufactured by: Novex Pharma, Richmond Hill, Ontario Canada
L4C 5H2. Manufactured for: Apotex Corp. Weston, FL 33326. July 2003. FDA rev