To the best of my knowledge generic medications
have the same active ingredients, the same dosage form (tablets, capsules, suspension, and syrup) and are identical in the strength or concentration to brand name medications.
They may look different in shape, size and colors. There are strict guidelines that the generic medication has to meet in order to be called therapeutically equivalent and be marketed to you.
To be approved by the Food and Drug administration here, the amount of medication absorbed and the time that it takes the medication to be absorbed by the generic has to be within a certain percent of the brand name medication.
Even with these guidelines, there may be small differences between medications manufactured by different companies. In many cases, these differences will not dramatically change the way people respond to the medicine, but, in some people, even these small differences may be important. Usually, if a person can be kept on the same manufacturer’s product, they can be effectively and safely treated.
I hope this reassures you.