Original formula AlkaSeltzer contains:

Active Ingredients: per tablet: Aspirin (325 mg), Sodium Bicarbonate (1916 mg), Citric Acid (1000 mg)

AlkaSeltzer Gold (without aspirin) contains:

Active Ingredients: Each tablet contains:: Sodium Bicarbonate (958 mg (Heat Treated)), Citric Acid (832mg), Potassium Bicarbonate (312 mg)

There are many many other formulas:
Including this new Morning Relief:

Active Ingredients: Aspirin (500mg) (Analgesic), Caffeine (65mg) (Alertness Aid/ Pain Reliever Aid)
Inactive Ingredients: Acesulfame Postassium, Aspartame, Citric Acid, Dimethicone, Dimethylpolysiloxane Powder, Docusate Sodium, Flavor, Mannitol, Povidone, Sodium Benzoate, Sodium Bicarbonate

Maximum strength formula:
Active Ingredients: (in each tablet): Aspirin 500 mg (Analgesic), Citric Acid 1000 mg (Antactid), Sodium Bicarbonate (heat-treated) 1985mg (Antacid)

Two of the max strength= 1000mg of aspirin


The quantities of the buffers are not given for every product. Morning Relief is similar to
The original Anacin (the one with aspirin) and contains caffeine. This product is higher in aspirin also.

There are cold formulas, and heartburn ones:
http://www.drugstore.com/search/sear...o.x=12&Go.y=16

There are new ones even that have the "name" AlkaSeltzer but are NOT
effervescent (they are syrups).

I think the citrate and bicarb are as important or more so than the aspirin,
for relieving BURNING pain. The delivery system of effervescence is also
important. Taking soda mint TABLETS, will not give the same response.
I believe that the SPEED of absorption, floods the body temporarily and
gets to the tissues to buffer the acid at the nerve endings. Taking tablets,
slows absorption, and when the buffers do get absorbed they are less in
concentration and diluted out quickly by the body's own buffer systems.
Hence it is the FIZZ that counts.

Also remember some drugs can cause acidosis:
metformin (Glucophage, Fortamet)
Topamax
untreated or poorly controlled diabetes
poisons, like antifreeze, methanol
And excessive aspirin consumption as in high dose 24/7
very high dose Vit C intake
lung disorders like COPD
acetazolamide (diuretic for CNS edema or altitude sickness)

People with undiagnosed mitochondrial disorders (not common)
make more lactic acid during the energy phases in the mitochondria.
This lactic acid causes muscle pain/burning. If you suspect this, have poor
exercise tolerance etc, using l-carnitine can help. This boosts the
metabolism of fatty acids for energy instead of glucose, so lactic acid is less.