Do you mean lincomycin used together with gentamicin?

If asking about co-administration: use only under a prescriber's or veterinarian's direction. The combination can increase toxicity concerns, particularly kidney injury from gentamicin, and lincosamides can contribute to neuromuscular blockade. Risk is higher with dehydration, kidney disease, older age, or other nephrotoxic medicines.

Tell me whether this is for a person or an animal, and the infection or formulation involved.