Sodium Lactate
Each g of sodium lactate (anhydrous) represents approxi-
malely 8.9 mmol of sodium and of lactate. Sodium lactate
(anhydrous) 4.88 g is approximately equivalent to I g of so-
dium.
Sodium Lactate Solution (Ph. Eur.) is a clear, colourless.
slightly syrupy liquid: miscible with water and with alcohol.
It has a pH of 6.5 to 9.0. Sodium Lactate Solution (LISP) is a
similar preparation, with a pH between 5.0 and 9.0. It should
be stored in airtight containers.
Adverse Effects and Treatment
Excessive administration of bicarbonate or other
compounds that are metabolised to form the bicar-
bonate anion may lead to Hypokalaemia and meta-
bolic alkalosis, especially in patients with impaired
renal function. Symptoms may include mood chang-
es, tiredness, shortness of breath, muscle weakness
and irregular heartbeat. Muscle hypertonicity
twitching, and tetany may develop especially in hy-
pocalcaemic patients. Treatment of metabolic alka-
losis associated with bicarbonate overdose consist'
mainly of appropriate correction of fluid and elec
trolyte balance. Replacement of calcium, chloride.
and potassium ions may be of particular importance.
Excessive doses of sodium salts may also lead to so-
dium overloading and hyperosmolality .
Administration of sodium bicarbonate by mouth can
cause stomach cramps, belching, and flatulence. Ex-
travasation of irritant hypertonic sodium bicarbo-
nate solutions resulting in tissue necrosis at the
injection site has been reported following intrave-
nous administration.
Excessive doses of potassium salts may lead to hy-
perkalaemia . Oral administration of potas-
sium salts can cause gastro-intestinal adverse
effects, and tablet formulations may cause contact
irritation due to high local concentrations of potassi-
um.
Excessive oral administration of citrate salts may
have a laxative effect.
Effects on the gastro-intestinal tract. In addition to
minor gastro-intestinal effects (see above), spontaneous rup-
ture of the stomach, although an exceedingly rare event, has
been reported on several occasions following ingestion of so-
dium bicarbonate. The bicarbonate was believed to have re-
sulted in the rapid production of enough carbon dioxide to
rupture a stomach already distended with food.
Effects on mental state. Lactate infusions have been re-
ported to induce feeling of anxiety, especially in patients
with anxiety states, and have been used as a pharmacological
model in the evaluation of mechanisms involved in clinical
anxiety.' There has also been a report of a patient receiving
oral lactate (as calcium lactate) who was suffering from panic
disorder associated with agoraphobia, when lactate was dis-
continued, the patient reported a reduction in panic intensity
without a decrease in the frequency of attacks.
Epileptogenic effect. Alkalosis may precipitate seizures:
however, absence seizures have also been reported to be asso-
ciated with sodium bicarbonate administration in a child in
whom the serum pH was normal.
Precautions
It is generally recommended that bicarbonate, or
agents that form the bicarbonate anion after metab-
olism, should not be administered lo patients with
metabolic or respiratory alkalosis. hypocalcaemia
or hypochlorhydria. During treatment of acidosis.
frequent monitoring of serum-electrolyte concentra-
tions and acid-base status is essential.
Sodium-containing salts should be administered ex-
tremely cautiously to patients with heart failure,
oedema, renal impairment, hypertension, eclampsia.
or aldosteronism.
Potassium-containing salts should be administered
with considerable care to patients with renal or
adrenocortical insufficiency, cardiac disease, or oth-
er conditions that may predispose to hyperkalaemia.
Abuse : High doses of bicarbonate have been taken by ath
letes to enhance performance in endurance sports by buffe-
ing hydrogen ions produced in conjunction with lactic acid.
Bicarbonates have also been used to alkalinise the urine and
prolong the half-life of basic drugs, notably sympathomimetics
and stimulants, thereby avoiding detection, however, such
a practice may enhance toxicity.
Interactions
Alkalinisation of the urine by bicarbonate or bicar-
bonate precursors leads to increased renal clearance
of acidic drugs such as salicylates and barbiturates
Conversely, urinary alkalinisation prolongs the half-
life of basic drugs and may result in toxicity (sec
also under Abuse, above}.
The concomitant use of potassium-containing salt
with drugs that increase serum-potassium concen
trations such as ACE inhibitors and potassium-spar-
ing diuretics should generally be avoided.
Citrate suits taken by mouth can enhance the ab-
sorption of aluminium from the gastro-intestinal
tract.
Patients with impaired renal function are particularly
susceptible to aluminium accumulation and citrate-
containing oral preparations, including many effer-
vescent or dispersible tablets, are best avoided by
patients with renal failure taking aluminium-con-
taining compounds.
Pharmacokinetics
Administration of bicarbonate, such as sodium bi-
carbonate, by mouth causes neutralisation of gastric
acid with the production of carbon dioxide. Bicarbo-
nate not involved in that reaction is absorbed and in
the absence of a deficit of bicarbonate in the plasma,
bicarbonate ions are excreted in the urine, which is
rendered alkaline, and there is an accompanying di-
uresis.
Acetates such as potassium acetate and sodium ace-
tate, citrates such as potassium citrate, sodium acid
citrate, and sodium citrate, and lactates such as sodi-
um lactate are metabolised, after absorption, to bi-
carbonate.
Uses and Administration
Bicarbonate-providing salts are alkalinizing agents
used for a variety of purposes including the correc-
tion of metabolic acidosis, alkalinisation of the
urine, and use as antacids.
When an alkalinising agent is indicated for treating
Acute or chronic metabolic acidosis . the
Usual agent used is sodium bicarbonate. In condi-
tions When acute metabolic acidosis is associated
with tissue hypoxia. such as cardiac arrest and lac-
tic acidosis, the role of alkalinising agents such as
sodium bicarbonate is controversial.
Sodium lactate has been given as an alterna-
tive to sodium bicarbonate in acute metabolic acido-
sis, but is no longer recommended because of the
risk of precipitating lactic acidosis. In chronic hy-
perchloraemic acidosis associated with potassium
deficiency, potassium bicarbonate may be preferred
to sodium bicarbonate. The citrate salts of potassium
or sodium have also been used as alternatives to
sodium bicarbonate in treating chronic metabolic
acidosis resulting from renal disorders. Sodium bi-
carbonate, lactate and acetate, and potassium acetate
are used as bicarbonate sources in dialysis fluid.
The dose of bicarbonate required for the treatment
Of acidotic states must be calculated on an individual
basis, and is dependent on the acid-base balance and
electrolyte status of the patient. In the treatment of
moderate acidosis bicarbonate has been given by
mouth and doses providing 57 mmol (4.8 g sodium
bicarbonate) or more daily may be required. In acute
acidosis, sodium bicarbonate has been given intra-
venously by continuous infusion usually with a
1.26% (150 mmol per litre) solution or by slow in-
travenous injection of a stronger (hypertonic) solu-
tion of up to 8.4% (1000 mmol per litre) sodium
bicarbonate. For the correction of acidosis during
advanced cardiac life support procedures, doses of
50 mmol of sod bicarbonate (50 mL of an 8.4%
solution) may be given Intravenously to adults. Fre-
quent monitoring of serum-electrolyte concentra-
tions and acid base status is essential during
treatment of acidosis.
Sodium bicarbonate may be employed in the management of hyperkalaemia to promote the intracellular uptake of potassium and correct associated acidosis.
Sodium bicarbonate, sodium citrate, and potassium
citrate cause alkalinisation of the urine. They may
therefore be given to relieve discomfort in mild uri-
nary-tract infections and to prevent the de
velopmeni of uric acid renal calculi in the initial
stages of uricosuric therapy for hyperuricaemia in
chronic gout (for example, see Probenecid).
In both cases, they are administered with a liberal
fluid intake, usually by mouth, in divided doses of
up to about 10 g daily. Sodium bicarbonate has also
been used with a diuretic in the treatment of acute
poisoning from weakly acidic drugs such as pheno-
barbitone and salicylates to enhance their excretion.
bul this process, which is known as 'forced alkaline
diuresis', is generally no longer recommended.
When administered by mouth, sodium bicarbonate
and potassium bicarbonate neutralise acid secre-
tions in the gastro-intestinal tract and sodium bicar
bonate in particular is therefore frequently included
in antacid preparations . To relieve dyspep-
sia doses of about I to 5 g of sodium bicarbonate in
water have been taken when required. Sodium eit
rate has been widely employed as a 'clear' (non-par-
ticulate) antacid, usually with an H;-receptor
antagonist, for die prophylaxis of acid aspiration as
sociated with anaesthesia . Sodium bicar-
bonate is also used in various preparations for
double-contrast radiograph}' where production of
gas (carbon dioxide) in the gastro-intestinal tract is
necessary. Similarly, solutions containing sodium
bicarbonate or citrate have been used to treat acute
esophageal impaction .
Sodium bicarbonate and sodium or potassium cit
rate are used as buffering or alkalinising agents in
pharmaceutical formulation. Sodium bicarbonate
and anhydrous sodium citrate are used in efferves-
cent tablet formulations.
Individual salts also have other specific uses. A 5Β°/r'
solution of sodium bicarbonate can be administered
aΒ» ear drops to soften and remove ear wax. Sodium
bicarbonate injection has been used to treat extrava
sation of unthracycline antineoplastics al-
though as mentioned in Adverse Effects, above
hypertonic solutions may themselves cause necro
sis.
Sodium citrate has anti-clotting properties and is
employed, as sodium acid citrate, with other agents
in solutions for the anticoagulation and preservation
of blood for transfusion purposes. Similarly, sodium
citrate 3% irrigation may be useful for the dissolu-
tion or blood clots in the bladder as an alternative to
sodium chloride 0.9%. Enemas containing sodium
citrate are given rectally as osmotic laxative.
Sodium citrate is also a common ingredient in cough
mixtures.
Eye disorders. Sodium citrate eye drops have been em-
ployed in the management of certain ocular injuries. It has
been suggested that corneal epithelial defects due to chemical
weapon injuries and lasting for more than one week or those
accompanied by limbal ischaemia require intensive topical
therapy with eye drops of sodium citrate 10% and of potassi-
um ascorbate 10%. Such therapy is said to prevent late cor-
neal melting and to permit the continuation of local
corticosteroid therapy as necessary.' The two types of eye
drops are given in alternate doses and are believed to act by
mopping up free oxygen radicals after chemical burns'
Sodium bicarbonate is also used in the management of
blepharitis, an inflammation of the margin of the eyelids that
may be caused by a variety of conditions, it may be allergic
in nature or associated with seborrhea of the scalp. Infection
of the eyelids can produce ulcerative blepharitis. a condition
characterised by the formation of yellow crusts which may
glue the eyelashes together. Parasites occasionally cause
blepharitis. The condition is first treated by cleaning the eyes
and eyelids with sodium bicarbonate solution or a suitable
bland eye lotion; simple eye ointment or diluted baby sham
poo can also be used to soften crusts to aid removal, if an
infection is present suitable antibiotic eye drops or ointment
mav be used once the crusts have been removed.
Long-term management consists of daily cleansing of the lid
margins with a bland eye lotion.
Osteoporosis. Potassium bicarbonate administered by
mouth in a dose of I to 2 mmol per kg body-weight daily for
18 days in 18 postmenopausal women was found to improve
calcium and phosphorus balance, reduce bone resorption and
increase its formation. However, elderly subjects with renal
impairment might be at risk of hyperkalaemia with the doses
used and long-term studies would be required before this
emerged as an effective treatment or preventative strategy for
postmenopausal osteoporosis .
Renal calculi. Citrate forms soluble complexes with calci-
um, thereby reducing urinary saturation of stone-forming cal
cium sails. Potassium citrate has a hypocalciuric effect when
given by mouth, probably due to enhanced renal calcium ab-
sorption. Urinary calcium excretion is unaffected by sodium
citrate, since the alkali-mediated hypocalciuric effect is offset
by a sodium-linked calciuresis.' An uncontrolled study has
demonstrated that potassium citrate may be beneficial in re-
ducing the rate of stone formation in patients with hypocitra-
turia. As mentioned in Uses above, sodium bicarbonate or
sodium or potassium citrate may also be employed for their
alkalinising action, as an adjunct to a liberal fluid intake, to
prevent development of uric acid renal calculi during uricosli-
ric therapy.
Unnav. alkalinisation with sodium bicarbonate, sodium cit
Rate, or potassium citrate may be useful in the management of
cystine stone formation in patients with cystinuria.