The RNU6-87P gene, also referred to as a small nuclear RNA gene, plays a critical role in the biogenesis of small nuclear ribonucleoproteins (snRNPs), which are essential for pre-mRNA splicing in eukaryotic cells. Here is a detailed overview based on your requests:

### 1. Associated Genes
RNU6-87P is part of a larger group of U6 small nuclear RNA genes, which includes other U6 genes involved in the splicing machinery. However, the specific associations beyond this family are not well-documented or defined in literature and databases. As a pseudogene, RNU6-87P may not directly link to specific functional genes but could have regulatory roles or be part of larger genomic contexts related to snRNA.

### 2. Aging and Age-related Diseases
While specific information about RNU6-87P’s direct involvement in aging or age-related diseases may not be extensively documented, alterations in the expression of small nuclear RNAs, including those involved in splicing, have been implicated in various age-related conditions. For example, defects in RNA processing and splicing mechanisms, which involve U6 RNA, are often associated with neurodegenerative diseases, cancer, and other age-related disorders. Additionally, maintaining proper splicing function is crucial for cellular senescence and overall organismal longevity.

### 3. Drug Interactions
As of now, there is no specific information about drugs or drug classes known to directly interact with the RNU6-87P gene. However, certain antitumor compounds and drugs modulating splicing factors or snRNPs indirectly could affect the activity of pathways involved with this gene, but precise details would require specific context and additional experimental evidence.

### 4. Pathways and Biological Processes
RNU6-87P is involved in several significant biological processes, though it is part of a pseudogene context. This gene is primarily linked to:

- **RNA Splicing**: The main biological process RNU6-87P is associated with includes the splicing of pre-mRNA. U6 snRNA serves as a component of the spliceosome, a complex responsible for the removal of introns from pre-mRNA.
- **Gene Expression Regulation**: Through its role in splicing, RNU6-87P indirectly influences gene expression levels and the maturation of mRNA.
- **Ribonucleoprotein Complex Assembly**: It plays a role in the assembly and function of the U6 snRNPs which are crucial for the pre-mRNA splicing pathway.

In summary, RNU6-87P is a part of the U6 small nuclear RNA family influencing RNA splicing and potentially contributing to cellular aging mechanisms. However, the specific functional implications and interactions of RNU6-87P, especially pertaining to pharmacology and age-related diseases, remain areas for further exploration.